The gastric emptying of a 0.25 M sodium bicarbonate solution was studied in rats with metabolic acidosis induced by a previous (6 hours) orogastric infusion of a 0.5 M ammonium chloride solution. Two control groups were used: one previously infused with 0.5 M sodium chloride and the other with water, in the same volume that further solutions. Every animal was fed with 2 ml/100 g of its weight of these solutions. The test meal (bicarbonate solution) was utilized containing 6 mg% red fenol as a marker. The gastric retentions were determined 6 hours after those first meals at 5, 10, 20 and 30 minutes. The results demonstrated that the gastric retentions of the bicarbonate solution were significantly lower in the acidotic group than that one of water group (at 20 minutes) and that one of the sodium chloride (at 10, 20 and 30 minutes). The data here presented suggest that metabolic acidosis accelerates the gastric emptying of a sodium bicarbonate solution.2923-7