The objective of this retrospective study was conducted to determine the clinical pregnancy outcome in women with letrozole ovarian stimulation in artificial insemination by donor (AID).In this study,939 letrozole cycles and 130 letrozole plus gonadotropin cycles were included from December 2012 to December 2015.Stimulation protocols of AID cycles included 939 letrozole (LE) cycles and 130 LE +Gn cycles.LE was given in a dose of 100mg for 5 days starting on days 3 or 5 of the menstrual cycle.Gn injections were given in the form of rFSH or uFSH after day 9 of menstrual cycle and the dose was adjusted according to the follicle response.