AIM: To examine clinical nurse supervisors' styles, in terms of models, organization, focus on supervision and theories used in supervision, as well as their perceptions of ethical dilemmas within health care. BACKGROUND: The importance of clinical supervision in clinical practice has been reported. However, literature dealing with its implementation is rare. METHODS: This study is a descriptive-correlational study. Data were collected by means of a questionnaire from two groups of nurse supervisors randomly selected from a university (n = 55) and a hospital (n = 31). Data were analysed using descriptive and inferential statistics. RESULTS: The models most frequently used were 'case-oriented' and 'decision-making oriented'. The nurse supervision was reported as being organized on a one-to-one basis. The focus of supervision was on 'patient problems' and 'cooperation in team'. The theory most commonly used was the theory of reflection. The supervisors' perceptions of moral dilemmas were related to 'decision making' and actions impacting on quality of care resulting from their supervisor styles. CONCLUSION: By correlating the supervisors' styles and their perceptions of ethical dilemmas, we conclude that it is important to contribute to further research on supervisors' styles in order to ensure successful supervision.