The purpose of this study was to evaluate the effectiveness of buserelin acetate (BA) for triggering endogenous LH surge before oocyte retrieval in clomiphene citrate (CC) or CC hMG cycles. Patients were divided into two groups: a buserelin group, which consisted of patients treated with BA for 73 cycles 34–36 hours before oocyte retrieval, and an hCG group, which consisted of patients treated with hCG for 89 cycles 34–36 hours before oocyte retrieval. Rate of oocyte retrieval, ratio of metaphase II oocytes, fertilization rate in ICSI, fertilization rate in IVF, ratio of good cleaved embryos, rate of blastocyst development and pregnancy rate were 59.1%, 74.3%, 78.8%, 78.4%, 64.6%, 50.0% and 8.3%, respectively in the buserelin group and 63.2%, 71.3%, 80.6%, 67.6%, 58.6%, 66.7% and 12.5%, respectively, in the hCG group. There were no significant differences in those results between the groups. In conclusion, BA is present terse should be used for a conclusion effective for triggering LH surge before oocytes retrieval in CC or CC hMG cycles.