The purpose of this study was to clarify the adsorption of cisplatin on regenerative-medicine (RM) gelatin sponge, and to verify the relationship between the cisplatin release pattern of cisplatin-adsorbed RM gelatin sponge and the dissolving time of RM gelatin sponge. We tested various RM gelatin sponges, one with a molecular weight of 50000 Daltons (RM-50 gelatin sponge) that is 100% saline soluble at 24 h, RM-50-120 (heated at 120°C) that is 54.3% saline soluble at 24 h, and RM-50-140 (heated at 140°C) that is 15.8% saline soluble at 24 h. We investigated the production of cisplatin-adsorbed RM gelatin sponge and measured free cisplatin released from cisplatin-adsorbed RM gelatin sponge. There was no significant difference in the weight of adsorbed cisplatin among the RM-50, RM-50-120, and RM-50-140. The results mean that cisplatin adsorbs onto RM gelatin sponge irrespective of heating temperature. The average adsorbed weight of cisplatin per gram of RM gelatin sponge was 29.3 mg, which was approximately five times more than that per g previously reported for Gelpart (non-soluble gelatin sponge, clinically available). Cisplatin release in the RM-50 gelatin was the most rapid at only 1 h after incubation; it was released gradually and increasingly in the RM-50-120 gelatin, and released slowly in the RM-50-140 gelatin for 24 h incubation. Cisplatin-adsorbed RM gelatin sponge released cisplatin proportional to the dissolving time of RM gelatin sponge, indicating that the cisplatin release time can be controlled by heating for sterilization of RM gelatin sponge.