Introduction: Previous research suggests that, relative to generating a differential diagnosis, deliberate reflection during practice with clinical cases fosters learning from a subsequently studied scientific text and promotes interest in the subject matter. The present experiment aimed to replicate these findings and to examine whether motivational or cognitive mechanisms, or both, underlie the positive effects of reflection. Methods: A total of 101 5th-year medical students participated in an experiment containing four phases: Students (a) diagnosed two clinical cases of jaundice-related diseases either through deliberate reflection or differential diagnosis; (b) reported their situational interest and awareness of knowledge gaps; (c) studied a text about jaundice, either under free or restricted time; and (d) recalled the text. Outcome measures were text-recall, situational interest and awareness of knowledge gaps. Results: A main effect of diagnostic approach on recall of the text was found, with the reflection group recalling more studied material than the differential diagnosis group (means: 72.56 vs 58.80; P =.01). No interaction between diagnostic approach and study time (free or restricted) emerged, nor was there a main effect of the latter. Relative to the differential diagnosis group, students who reflected upon the cases scored significantly higher on both situational interest (means: 4.45 vs 3.99, P <.001) and awareness of knowledge gaps (means: 4.13 vs 3.85, P <.01). Discussion: Relative to generating differential diagnoses, reflection upon clinical cases increased learning outcomes on a subsequent study task, an effect that was independent of study time, suggesting that cognitive mechanisms underlie this effect, rather than increases in motivation to study. However, higher scores on situational interest and awareness of knowledge gaps and a tendency towards larger gains when time was free suggest that higher motivation may also contribute to learning from reflection.