Objective: to test the hypothesis that midwives who had completed the 20-hour WHO/UNICEF Breastfeeding Management Course would score significantly higher on a validated, quantitative measure of breast-feeding support skills, the Breastfeeding Support SkillsTool (BeSST), than a central group of midwives who had not undertaken the course. Design: breast feeding support sk:ills were assessed using a between-subjects design conducted in midwives who had not attended the course and at two weeks following the 20 hour course, Participants and setting: two groups, consisting of 13 pre- and 15 post-course midwives, compared, The research was carried out at four hospital sites in the UK, three of which had undertaken the 20 hour course and one which had not adopted the course, Findings: scores on the BeSST were significantly higher in the post-course group (mean 29.9) than in the pre-course group (mean = 19.8), t (23.39) = 2.94, P < 0.01, Key conclusions: it is clear that breast-feeding support skills, as demonstrated by the BeSST, are significantly improved two weeks following the 20-hour WHO/UNICEF Breastfeeding Management Course. Implications for practice: by demonstrating the effectiveness of the 20-hour course in teaching breast-feeding support skills, additional hospitals may be encouraged to adopt course and thereby contribute further to the advancement of optimum breast-feeding practices, Furthermore, this approach to assessment may be transferred to other areas of midwifery practice enabling the effective evaluation of courses and assessment of student learning, (C) 2000 Harcourt Publishers Ltd.