OBJECTIVE: To investigate the efficacy and safety of famotidine treatment for stress ulcers in neonates. MEYHODS: Fifty-four neonates with stress ulcers from 2001 to 2006 were enrolled. Seven cases were confirmed with stress ulcers by gastroscopy. Famotidine was administered intravenously at a dosage of 0.5 mg/kg every other 12 hrs. After cessation of hematemesis and vomiting, famotidine was administered once a day for two days. Primary diseases and complications were concurrently treated. Clinical symptoms and gastric pH were assessed before and after famotidine treatment. Possible adverse effects of famotidine treatment-related were observed. RESULTS: After 24 hrs of famotidine treatment, hematemesis and vomiting ceased in 52 patients (96.3%). Clinical symptoms disappeared in all of the 54 patients 48 hrs after famotidine treatment. Gastric pH value increased 6, 12, 24, 36 and 48 hrs after famotidine treatment from 2.07±0.22 (before treatment) to 5.01-5.15 (P﹤0.01). All of the 54 patients were successfully treated. Famotidine treatment did not lead to abnormal respiration, heart rate and blood pressure. Loss of appetite, nausea, vomiting, diarrhea, constipation and rashes were not seen after famotidine treatment. There were significant differences in white cell count, platelet count and hepatic enzyme levels before and after famotidine treatment. An augmented side effect of the other drugs concurrently used due to famotidine treatment was not noted. CONCLUSIONS: Famotidide is effective and safe for the treatment of stress ulcers in neonates.