Increased gestational weight gain is associated with higher rates of complications of pregnancy and delivery. Gestational weight gain of 9-12 Kg has been associated with the best outcome for both mothers and infants. However, weight gain in most pregnant women is not within this range, perhaps due to the difficulty of calculating the exact quantity, timing and duration of dietary restriction in individual patients that would bring their weight gain within the normal range. There is therefore a need to develop a drug or food supplement that would reduce weight gain without causing adverse effects on the fetus. Aframomum melegueta is widely used in Nigeria by most people including pregnant women for various purposes. It is against this background that the present investigation examines the possibility of its beneficial effects on pregnancy, using Sprague Dawley rat as the animal model. Twenty female and ten male Sprague-Dawley rats of proven fertility from a pilot study were randomly mated in groups of two females and one male. Three days later, female rats in the experimental groups were given intra-peritoneal injections of 0.5 mg, 1 mg, 1.5 mg and 2 mg of aqueous extract of alligator pepper respectively while the control had 2 ml of distilled water. All rats were observed for 18-25 days. There was a significant [P<0.05] reduction in gestational weight gain of the experimental rats. The litters were not adversely affected. It is suggested that the active component of aqueous extract of alligator pepper be determined because of its beneficial effect of gestational weight gain reduction.