Background Electrocardiogram (ECG) interpretation is a core skill required of all doctors. Despite this, ECG interpretation remains suboptimal among medical students and doctors in clinical practice. This study assessed the impact of a short period of ECG teaching provided to medical students on completion of their academic curriculum. The primary outcome was the impact on students’ knowledge. The secondary outcome was the impact on confidence in ECG interpretation. Methods and Results Prospective cohort study of the impact of 2 hours of ECG teaching delivered by Cardiology trainees to final year medical students. Standardised 10 question examinations were given before and after the session. Questionnaires were given to assess confidence in ECG interpretation. Of 150 students who received teaching, 141 completed the pre-course examination and 139 completed the post-course examination (mean age 25.1 years; 55.5% female; 81.1% undergraduate). There was a statistically significant improvement in results after the course (p <0.001). The improvement was most significant in the assessment of heart rate and STEMI identification. Thirty-nine students completed feedback questionnaires. There was a statistically significant improvement in confidence in ECG interpretation (p <0.001). Conclusions This study showed an improvement in both ECG knowledge and confidence in ECG interpretation following 2 hours of teaching. The assessment of simple concepts such as heart rate improved more significantly than complex concepts such as conduction abnormalities. Our findings suggest a benefit from dedicated ECG revision programmes to enhance ECG knowledge and confidence in ECG interpretation.