Aim This is an evaluation study of the impact of the adapted RCN Clinical LeadershipProgramme on the development of leadership competencies of nurse leadersin Switzerland.Background Transformational leadership competencies are essential for deliveringhigh-quality care within health-care organizations. However, many countries haveidentified a lack of leadership skills in nurse leaders. Consequently, the developmentof leadership competencies is a major objective for health-care centres.Methods This article describes the quantitative results of a mixed methods study.A one-group pre-test–post-test quasi-experimental design was used. A conveniencesample of 14 ward leaders were assessed three times using the Leadership PracticesInventory (LPI). Descriptive and inferential data analysis techniques were employed.Results In total 420 observer-assessment questionnaires and 42 self-assessmentquestionnaires were distributed. Our main finding was that nurse leaders followingthe programme, demonstrated significant improvement in two subscales of the LPI –inspiring a shared vision and challenging the process.Conclusion This study showed improvement in two leadership practices of nurseleaders following a programme that has been adapted to Swiss health care.Implications for nursing management Findings concur with others studies thatsuggest that investments in educational programs to facilitate leadership skills innurse leaders are justified.