The aim of this study was to describe factors defined by nurses as influential upon the development of competence and skills in supervision. Although clinical supervision has been widely studied and described during the last decade, influential factors regarding the development of supervisory competence, as defined by clinical supervisors themselves, is little documented. Focus group interviews were analysed using methods of qualitative content analysis as described by Kvale. Factors related to three areas of importance for the development of competence and skills in student supervision are defined by nurses in this study. They are didactics, role functions and organizational framework. Didactic factors described included: integration of theory and practice; reflection on clinical situations; clarification of supervision aims and student evaluation. Role function factors were described as: feelings of security and awareness in supervision, differentiation between student and supervisor roles and the meaning attached to being a role model. Framework factors included nursing faculty and clinical field expectations. An understanding of how nurses describe what they need to support their development as clinical supervisors gives a basis for the development of postgraduate education in clinical supervision. Competent clinical supervisors can be better able to support students as they build bridges between theory and practice.