Educational strategies that promote the development of clinical reasoning in students remain scarce. Generating self-explanations (SE) engages students in active learning and has shown to be an effective technique to improve clinical reasoning in clerks. Example-based learning has been shown to support the development of accurate knowledge representations. The purpose of this study was to investigate the effect of combining student's SE and observation of peer's or expert's SE examples on diagnostic performance. Fifty-three third-year medical students were assigned to a peer SE example, an expert SE example or control (no example) group. All participants solved a set of the same four clinical cases (training cases), 1-after SE, 2-after listening to a peer or expert SE example or after a control task, and 3-1 week later. They solved a new set of four different cases (transfer cases) also 1 week later. For training cases, students improved significantly their diagnostic performance overtime but the main effect of group was not significant suggesting that students' SE mainly drives the observed effect. On transfer cases, there was no difference between the three groups (p > .05). Educational implications are discussed and further studies on different types of examples and additional strategies to help students actively process examples are proposed.