Disordered gastrointestinal motility is an often overlooked clinical problem. Delayed gastric emptying of solid and/or liquid meal in patients with both type 1 and type 2 diabetes mellitus occurs in approximately 50% of these patients. Gastric emptying time (GET) was studied in seventy four non-insulin dependent (type 2) diabetic out-patients by using radionuclide gamma-photography with Tc-99m phytate solid experimental meal. Thirty nine of them received Tc-99m phytate liquid test meal on the next day. Forty six normal healthy volunteers acted as controls. The results showed that solid GET in patients with type 2 diabetes mellitus was significantly delayed (149.44 +/- 64.0 min) as compared with that in the control group (88.7 +/- 14.2 min) (p < 0.001). Fifty three among these 74 diabetic patients had delayed solid GET, accounting for 71.6%. Only 5 of 39 (12.8%) diabetic patients showed delayed liquid GET (average 38.7 +/- 35.3 min; control 46.2 +/- 11.1 min). There were no differences in sugar control, duration of the disease, and upper gastrointestinal symptoms between patients with delayed GET and those with normal GET. We concluded that delayed gastric emptying is very common in patients with non-insulin dependent diabetes mellitus and which has no direct correlation to blood sugar control, duration of the disease, and upper gastrointestinal symptoms. Radionuclide solid gastric emptying test is a both safe (low radioactivity) and convenient (non-invasive) diagnostic tool in non-insulin dependent diabetic gastroparesis.