GnRH was administered subcutaneously in hourly pulses for 10 consecutive nights to two immature males with Kallmann's Syndrome using a portable, battery-operated infusion pump adapted for home use. Pulsatile GnRH produced a progressive increase in urinary gonadotropin excretion, a significant increase in mean basal plasma FSH, pulsatile LH release, and an increased LH response to a standard 3 hour GnRH infusion test. One subject developed a striking increment in plasma testosterone in response to GnRH pulses, as well as a biphasic LH response to the 3 hour infusion.