Gastric emptying was studied in 10 insulin-treated, long-standing, diabetic out-patients with upper gastrointestinal, dyspeptic symptoms. Autonomic neuropathy, mucosal lesions and chloropeptic hyposecretion were excluded. Gastric emptying of a labelled solid meal (99mTc-sulphur colloid-infiltrated chicken liver) was clearly delayed by comparison with normal subjects: the mean gastric emptying half-time was almost 5-times longer (245.6 vs 52.5 min), and the gastric emptying rate at 120 min was 75% slower. Cisapride 10 mg i.v. significantly accelerated both parameters, and placebo had no effect upon them. In conclusion, gastroparesis may be present in diabetics without autonomic neuropathy, and cisapride may improve gastric emptying in such patients.