The present studies were designed to advance theoretical understanding of employee adjustment during organisational change. There were two broad aims of the thesis. Firstly, the role of organisational climate factors in facilitating employee adjustment during change was examined by testing models based on Lazarus and Folkman's (1984) cognitive-phenomenological account of stress and coping processes. In particular, the concept of coping resources was expanded to examine organisational factors rather than individual attributes. Secondly, the extent to which organisational sub-groups differ in their perceptions of climate and levels of adjustment indicators during change was investigated. The research also aimed to inform diagnostic processes within organisational change management by examining the applied value of the empirical findings of each of the studies. The first two studies were empirical tests of a theoretical model of employee adjustment. Study 1 tested a model of employee adjustment to organisational change that examined employee well-being and job satisfaction as outcomes of positive adjustment during change. Firstly, pilot interviews with 67 hospital employees enabled salient aspects of the organisational climate that may facilitate adjustment during organisational change to be confirmed. Next, 779 employees in the same organisation completed a structured questionnaire that examined their perceptions of organisational coping resources, appraisals of change and adjustment indicators. Confirmatory factor analyses established the sound measurement properties of the proposed model and structural equation analyses provided evidence that supported the majority of theoretical predictions. Overall, the final model showed that employees who had positive perceptions about employee relations within the hospital, strong beliefs about the quality of patient care, and felt supported by their supervisors were more positive in their appraisals of the change and reported better personal adjustment. The effects of climate variables on adjustment were direct and indirect (mediated by change appraisals). A particularly influential variable in the model was the effectiveness of employee relations within the organisation. Study 2 tested a model of employee adjustment to organisational change which examined organisational commitment, turnover intentions and absenteeism as outcomes of positive adjustment during change. Firstly, as in Study 1, pilot interviews with 20 state public sector employees enabled salient elements of the organisational climate that may function as resources for coping with organisational change to be confirmed. Next, 877 employees in the same organisation completed a structured questionnaire that examined their perceptions of organisational coping resources, appraisals of change and adjustment indicators. Like Study 1, confirmatory factor analyses established the sound measurement properties of the proposed model and structural equation analyses provided evidence which supported most of the theoretical predictions. Overall, the final model showed that employees who had positive perceptions about customer service, believed that their leaders communicated a vision for the organisation, and felt supported by their supervisors were more positive in their appraisals of the change and reported better personal adjustment. The effects of climate variables on adjustment were direct and indirect (mediated by change appraisals). The extent to which leaders exhibited a vision for the organisation emerged as an important predictor in the model. Together, the results of studies 1 and 2 provided evidence that organisational climate variables are important predictors of the way employees appraise and respond to organisation change. The next two studies presented were focused on group differences in the model variables from studies 1 and 2. Study 3 investigated group differences in perceptions of climate and levels of adjustment during organisational change as a function of an employee's organisational level. The pilot interviews revealed that an employee's organisational level was the most salient source of sub-group identification in the climate of a public sector department. Survey data from study 2 were analysed using Multivariate Analysis of Variance (MANOVA). The responses of 669 public sector employees were grouped into 3 categories: lower, middle and upper level employees. Results revealed that upper level staff reported higher levels of adjustment during change, across a range of indicators. Study 4 investigated occupational group and organisational level differences in perceptions of climate and levels of adjustment during organisational change. The pilot interviews in this organisation revealed that it was an employee's occupational group membership that provided the most salient group delineator in the hospital climate. Survey data from Study 1 were analysed using MANOVA. The responses of 732 hospital employees were grouped into 4 major occupational categories: medical, nursing, allied health and non-clinical staff. Participants were also grouped on the basis of whether they occupied a management or non-management position. Results revealed statistically significant differences between groups and an interaction between occupation and level. Non-clinical staff were less well adjusted during change than other occupational groups. Managers appraised change as more stressful than non-managers, but felt more in control of the situation. Together, the results of Studies 3 and 4 highlighted the importance of examining employee perceptions at the sub-group level when implementing change and indicated the need for interventions to be targeted at the sub-group level. Overall, the research reported in this dissertation extended a theoretical model of employee adjustment to change and improved the application of the model. This outcome was achieved by investigating the role of environmental coping resources drawn from the organisational climate in improving employee adjustment during change and the degree to which groups differed in their perceptions of these variables. Climate and change appraisal factors were linked with a range of important individual/organisational outcomes such as employee well-being, job satisfaction, organisational commitment, turnover intentions and absenteeism. Differences in perceptions of climate and levels of adjustment during change were also observed at the organisational sub-group level. The findings of the research have implications for the effective management of organisational change. Change should be implemented in conjunction with ongoing organisational development processes involving diagnostic research that identifies the elements of climate that employees draw upon for support in the process of adjustment. Interventions should be based on improving and strengthening these resources. Diagnostic processes should also pay attention to the salient groupings of staff within an organisation so that interventions can be targeted specifically to relevant sub-groups.