OBJECTIVE Diabetic gastroparesis is a common complication seen in 20-50% of patients due to autonomic neuropathy involving vagal supply. Cisapride, a specific gastrointestinal cholinomimetic agent may thus be effective. METHODS Fifty-one diabetic patients (age 12-65 years) of disease duration > 5 years were assessed for symptomatic gastroparesis, other diabetic complications and glycemic control. Gastric emptying time (GET) was estimated using a solid meal method (99mTc labeled rice based idli) and patients randomized to receive either cisapride or placebo for a period of 2 weeks. Cisapride was administered in a dose of 10 mg TID. GET and symptom scores were reassessed on the therapy after 2 weeks. RESULTS Twenty nine of 51 (56.8%) patients had gastroparesis. Mean GET in the gastroparesis group was 141 +/- 66 minutes compared to 24.53 +/- 10 minutes in the non gastroparesis group (p < 0.01). GET decreased by 72% amongst the patients who received cisapride compared to 23% in the placebo group (p < 0.001). Symptom scores also improved in the cisapride group; no adverse effects were noted. CONCLUSIONS Cisapride improves the symptom score and the solid gastric emptying time in patients suffering from diabetic gastroparesis.