Abstract: A method for synchronizing ovulation in cattle by sequential injection of hormones is disclosed. A hormone selected from the group consisting of gonadotropin releasing hormone (GnRH), luteinizing hormone (LH), or human chorionic gonadotropin (hCG) is administered to an open cow during an estrous cycle in order to stimulate follicle development. Prostaglandin F.sub.2.alpha. (PGF.sub.2.alpha.) is then administered to initiate corpus luteum regression about five to eight days after administration of the GnRH, LH or hCG. A second dose of GnRH, LH or hCG is then administered concomitantly with the PGF.sub.2.alpha. injection or up to about three days after the PGF.sub.2.alpha. injection. This second dose of hormone functions to stimulate the ovulation of a dominant follicle and the cow is then breed within one day of the administration of the second dose of hormone.