Gastrocystoplasty has been previously described as an effective method of bladder augmentation or replacement. Twenty-four female Wistar rats were divided into three groups of eight animals each: control (G1), partial gastrectomy with the gastric body (G2) and gastrocystoplasty with the gastric body (G3). The period of observation was 2 months and the parameter assessed was serum gastrin. Increases in serum gastrin were seen in 62.5% (5/8) of rats in group 2 and in 50% (4/8) of rats in group 3. Our results suggest that, in rats, hypergastrinemia is induced by the partial surgical removal of the gastric body and is not due to gastrocystoplasty.