M.Cur. (Nursing Management) / Assertiveness is the ability to express oneself and one’s rights without violating the rights of others (http: www.naidex.co.uk/page.cfml/link). The need for assertiveness is widely acknowledged in different work settings, and in order to manage the stress of working as part of a team every day, one has to become assertive. Acquiring and using assertiveness involves a simple and effective technique whose main object is to promote and maintain one’s personal health, self-esteem and healthy relationships with other people (Booyens, 2005:395). In the course of her work as a nurse manager in an academic hospital, the researcher became aware in an academic hospital setting that some professional nurses and nurse managers in an academic hospital setting were lacking assertive behaviour in their interactions and relationships with their colleagues. The purpose of the study was to explore and describe the kinds of assertive behaviour of professional nurses and nurse managers in the nursing units of two academic hospitals in the Pretoria region, in order to identify guidelines for effective assertive behaviour in such contexts. In this study a quantitative, descriptive and explorative design was used in order to obtain information from permanent professional nurses and nurse managers working in units of two academic hospitals in Pretoria. All of the nurse managers (n = 80) in these units were included in the study as the total sample. Four hundred and forty (n = 440) professional nurses and eighty (n = 80) nurse managers were eligible to participate in the study. Simple random sampling of the professional nurses was conducted to obtain a sample (n = 110). The method of data collection was a self-administered, structured questionnaire whose purpose was to explore and describe the assertive behaviour of professional nurses and nurse managers in academic hospital settings in the Pretoria region (Burns & Grove, 2005:398).Validity and reliability were ensured by using the principles of Riley, Wood, Clark, Wilkie and Szivas (2004:126) as well as the principles of Goddard and Melville (2001:46). Ethical standards for nurse researchers were adhered to. Descriptive statistics were arrived at by using SPSS (Version 20)