Ovarian stimulation in cases of poor ovarian responsiveness is an important challenge in in-vitro fertilization (IVF) programmes. Despite improvements in oocyte number and quality, an ideal ovarian stimulation strategy has yet to be defined. Here, the results of ovarian stimulation with recombinant follicle stimulating hormone (rFSH) in 28 poor responders to highly purified FSH (FSH-HP) with high basal concentrations of FSH are reported. The protocols used on the FSH-HP and rFSH cycles were identical with the sole exception of the FSH preparation: triptorelin 0.1 mg/day (gonadotrophin-releasing hormone, GnRH-agonist short protocol) and the starting FSH dose of 300 IU/day were administered from day 2 of the menstrual cycle. Ovarian outcome was classified as 'normal', 'intermediate' and 'poor', depending on the number of mature oocytes retrieved and the peak serum oestradiol concentration. Nine of the 28 subjects had an intermediate ovarian response to re-stimulation with rFSH. In the 26 patients who received human chorionic gonadotrophin on both cycles, re-stimulation resulted in a significant increase (P < 0.05) in the mean number of mature oocytes (2.4 +/- 1.4 versus 1.7 +/- 0.8), mean peak oestradiol concentration (606 +/- 252 versus 443 +/- 32 pg/ml) and fertilization rate (73.0 versus 53.3%). Four pregnancies were achieved. It is concluded that rFSH in a GnRH-agonist short protocol improves the ovarian outcome in poor responders to FSH-HP with high basal concentrations of FSH.