Objective This study aims to evaluate the effectiveness of the online Clinical Professional English course in enhancing the clinical English proficiency of eight-year medical program students, and further explore the students′ satisfaction with the course. Methods In this study, a convenience sampling method was adopted, with 60 students from the 8-year medical program (admitted between 2016 and 2018) at Peking University People′s Hospital selected as the research subjects, including 18 students from the first year, 24 students from the second year, and 18 students from the third year. Teaching effectiveness was assessed through pre- and post-course tests and satisfaction surveys of the online Clinical Professional English course. The course incorporated diverse digital resources, virtual case studies, pre- and after-course test, focusing on enhancing medical students′ understanding of professional English terminology, fluency in expression, and cross-cultural communication skills. Results The average scores increased from 10.60±2.59 to 16.27±2.15 (t=-12.974, P<0.001), demonstrating significant improvement in students′ mastery of professional terminology, fluency, and confidence in cross-cultural communication. Subjective feedback revealed that 66.7% (40/60)of students reported significant progress in professional vocabulary, and 58.3% (35/60) self-assessed increased confidence in cross-cultural communication. However, some students highlighted a lack of interactivity in online teaching. Conclusions Online Clinical Professional English course instruction significantly improves students′ mastery of professional terminology, fluency in expression, and confidence in cross-cultural communication, but there are shortcomings in terms of interactivity. Based on this, it can be inferred that a blended teaching model (combining online and offline learning) can more comprehensively meet students′ practical application needs for clinical professional English.