Aims <p>To evaluate the implementation effect of Chinese-English bilingual instruction in endocrinology system courses.</p> Methods <p>Students in the endocrine course with bilingual Chinese-English instruction form the experimental group (Group B, <i>n</i> = 581), while those with traditional Chinese teaching serve as the control group (Group A, <i>n</i> = 574). The effectiveness of bilingual instruction was evaluated through theoretical tests and questionnaires.</p> Results <p>The theoretical test results showed that Group B, which received bilingual instruction, had higher scores than Group A, which received traditional Chinese instruction. This indicates that bilingual instruction can enhance students’ understanding and performance in endocrinology courses. The two groups were confirmed to have a comparable level of English proficiency at the baseline, with no significant difference in the passing rate of the National College English Test Band 4 (Group A: 81.7%; Group B: 82.3%; <i>p</i> = 0.87). Most students believed that bilingual instruction was necessary and that the teaching reform had clear objectives. The students also highlighted the importance of their English proficiency and the need for effective teaching methods.</p> Conclusions <p>The results show that bilingual teaching plays a positive role in improving students’ professional knowledge and English proficiency and stimulating learning interests. However, there are also polarization problems caused by differences in students’ English foundations.</p>