This work describes a mentorship experience. Mentorship of novice teachers by experienced teachers is an important aspect in training teachers for universities. The strategy followed in this work consisted of a double improvement cycle (or clinical supervision cycle), based on the use of recordings of classes. Each of these cycles included planning, recording, viewing and analysis. Conclusions were reached in a final meeting after video analysis. In order to systematize the viewing, analysis and assessment of the videos, an observation test was employed. Class planning, contents, methodology, and verbal and nonverbal communication skills were evaluated using the test.