Follicular stimulation was compared in macaques receiving sequential gonadotropin treatment which was terminated after seven, eight, or nine days depending on the time required to attain preselected criteria of follicular maturation. Although estradiol levels and follicle sizes varied, the number of follicles and oocytes/animal, oocyte nuclear maturity, IVF rates and progesterone levels during the luteal phase were similar among groups. Reducing the duration of gonadotropin treatment to individualize follicular stimulation regimens does not compromise follicle or gamete quality.