Mitofusin-1 is one of the membrane profusion proteins that is present in the mitochondria wall. It has a role in mitochondrial fusion. Deletion of mitochondrial fusion proteins in oocytes leads to dynamic defects in mitochondria. Growth of implanted and after implantation embryo is an ATP-demanding step that involves a range of ATP-consuming events that require a small amount of ATP. The study aims to evaluate the mitofusin-1 in the serum and follicular fluid as a marker for the evaluation of embryo quality, in addition to the pregnancy rate in infertile females undergoing ICSI cycles. The cross-section study included 50 infertile couples who were prospectively recruited according to specific criteria at the" High Institute for Infertility Diagnosis and Assisted Reproductive Technologies" at AL-Nahrain University for one year. all participants have undergone oocyte pickup, ICSI, and embryo transfer. Mitofusin-1 levels were measured in serum on day 2 of the cycle and in follicular fluid on the day of ova pick-up. Showed important positive relations between follicular fluids mitofusin-1 with a total number of embryos (r=0.428 & p=0.002), GI embryos (r=0.335 & p=0.017) and GII embryos (r=0.295 & p=0.038). Out of 50 females, 14 (28.0 %) females became pregnant according to the results there were significantly higher follicular fluids mitofusin-1 levels in pregnant females (3.88±1.41 vs. 2.73±1.24 & p=0.007) compared to non-pregnant group. Also, the follicular fluids mitofusin-1 cut-off value was ≥2.89 ng/ml with sensitivity=71.4%, specificity=66.7%, positive predictive value 47.8%, negative predictive value 88.9%. Elevated MEN1 levels in the follicular fluid may affect positively IVF/ICSI outcomes (embryo quality, and pregnancy rate).