Background Peer-assisted learning has been shown to be constructive in numerous aspects of undergraduate medical education. The purpose of this study was to evaluate the effectiveness of peer-assisted teaching of medical English skills to non-native English-speaking students. Methods A medical English conversation course was conducted at Damascus University by a group of students. Targeted participants were intermediate level fellow students from the same program. A longitudinal study was carried out between 1st to 31st March 2019 to assess changes in self-assessment of English language skills among course participants. Pre- and post-course appraisal involved a review of previous experience with medical English language, a self-assessment of five English language skills, and an objective measurement of medical English knowledge. In addition, participants were requested to respond to a set of statements related to the importance and the usefulness of peer-assisted teaching of medical English skills. Paired-sample Student t-test was used to compare pre- and post-course appraisal results. Results 42 students attended the course and completed pre- and post-course appraisals in full. Data analyses showed a statistically significant increase in participants’ confidence in speaking medical English in public (p<0.001) and using English in various medical settings (presenting and discussing cases, writing clinical reports, interviewing patients and reading English medical texts). Objective measurements of medical English knowledge confirmed a significant increase in participants’ knowledge of methods of administration of therapeutics, knowledge of human body parts in English and familiarity with English medical abbreviations. Most participants agreed that peer-education was effective in teaching medical English skills to non-native English-speaking students and in increasing their confidence when using English in real-life medical scenarios. Conclusions The present study highlights the effectiveness of peer-assisted teaching of medical English skills to non-native English-speaking medical students. Further validation is required and should compare the effectiveness of traditional versus peer-assisted teaching approaches.