Purpose: Few studies have reported the effects of the flipped classroom (FC) on cardiovascular teaching. This study investigated students' performance after using the FC to teach electrocardiogram (ECG) recognition of acute myocardial infarction (AMI). Methods: We recruited 56 and 52 students in the FC and traditional lecture (TL) groups, respectively, through cluster sampling. The modified Course Evaluation Questionnaire and the open-ended question, which explored the general thoughts of the students, were applied to both groups. To evaluate the students' performance, the same post-class quizzes including questions on anterior, lateral, and inferior wall MI were presented as multiple-choice questions, which were answered using the interactive response system. The difference in questionnaire and final test scores between the FC and the TL groups was analyzed using a t test. Results: Compared with the students in the TL group, those in the FC group tended to obtain higher grades (91.05 ± 20.59 vs. 85.49 ± 26.25, p = 0.221). The percentages of the students who reached the median score was higher in the FC group than in the TL group (79.0% vs. 57.7%, p = 0.024). Moreover, compared with the TL group, the FC group exhibited better performance in recognizing inferior wall MI ECG (29.47 ± 2.94 vs. 26.47 ± 6.88, p = 0.005). Conclusion: Our results indicated that the use of the FC efficiently delivered knowledge regarding AMI ECG recognition, which improved students' performance and enhanced their curricular satisfaction. Additional large-scale prospective studies involving formative assessment and students' long-term performance evaluation are warranted.