This article addresses the issue of instructional guidance in reciprocal peer tutoring with task cards as learning tools. Eighty-six Kinesiology students (age 17-19 years) were randomized across four reciprocal peer tutoring settings, differing in quality and quantity of guidance, to learn Basic Life Support (BLS) with task cards. The separate and combined effect of two instructional guidance variables, role switching and role definition, was investigated on learning outcomes. In all settings student pairs were given 20 min to learn BLS. Individual student performance was measured before (baseline), immediately after (intervention) and two weeks later (retention). Repeated ANOVA showed strong learning gains but no significant differences between groups for total BLS scores. However, at retention significantly more students from the most guided condition remembered and consequently performed all BLS skills. It is concluded that guidance comprising role switching and role definition enhances skill retention in reciprocal peer tutoring with task cards. (Contains 2 figures.)