The research made in the current master thesis uses theoretical framework from the area of project management, voluntary labor turnover and performance appraisal. Prior research based on existing literary sources allows assuming that the following factors, such as job alternatives, knowledge intensity and nature of work have specific relevance for the emergence of voluntary labor turnover in project-based organizations. Employees of the case study company-AGR Field Operations´ Maintenance Engineering department were interviewed and surveyed in order to determine the relevance of those factors on the example of a concrete project-based organization. The obtained results indicate that the nature of work is more significantly related to the emergence of the voluntary labor turnover in the given case study department. Whereas availability of more job alternatives due to being close to the client or knowledge intensity factor of becoming more generalist do not have the same influence. During the course of the research it was discovered that the department uses outcome-based type of performance appraisal which is proved to be unsuitable in the given organizational settings. To that matter there were provided further suggestions in the field of performance appraisal. The current research will attempt to identify specific factors contributing to the emergence of the voluntary labor turnover specifically for project-based organizations. As well as it will attempt to give suggestions for improvement of the concrete case study department´s performance appraisal tools and thus supplement turnover reduction actions already put in place by the department management.