BACKGROUND: To maintain a high standard of quality nursing care the individual critical care nurse s competencies should be determined objectively. Few international guidelines describe the qualities required by critical care nurses to function effectively in a critical care unit. These guidelines often focus only on the education and training of critical care nurses. OBJECTIVE: To formulate and describe guidelines for the competency requirements of registered critical care nurses. METHOD: A focus group interview, a qualitative research method, was conducted as an open conversation in which each participant could ask questions, comment, or respond to comments. Interaction among the respondents was encouraged to stimulate in-depth discussion. The study was conducted within the framework of South African critical care nursing. RESULTS: The four main categories that were identified are as follows: professional competence, cognitive competence, interpersonal skills, and critical care patterns of interaction. These are described in detail along with a formulated guideline for critical care nurse competency requirements. CONCLUSION: This study describes an attempt to formulate objective guidelines for critical care nurses competency requirements.