Glucagon was administered to 20 volunteers as a 1 mg iv bolus, a 2 mg iv bolus, a 1 mg subcutaneous (sc) injection, and a 1 mg infusion. All 4 tests were followed by a significant human growth hormone (HGH) rise. In response to the 1 mg ½ hr infusion and the 1 mg sc injection, the rise was large, reproducible, and occurred in all tested subjects. The rise in HGH following the bolus injections was small. In response to bolus glucagon, 50% of the tested subjects did not exhibit an HGH rise greater than 2 ng/ml. It was concluded that either a 1 mg sc injection or a 1 mg ½ hr infusion of glucagon is a useful test in studying pituitary growth hormone release.