Diabetic autonomic neuropathy is a known complication of long-standing diabetes. The present study was designed to study the prevalence of asymptomatic prolonged gastric emptying (GE) in young patients with IDDM and its correlations with disease duration and autonomic nerve function. The study population included 40 poorly controlled patients, mean age 17.6 ± 4.6 years, with a disease duration of 1-17.5 years, and 20 age- and sex-matched controls. Autonomic nerve functions were assessed by standard cardiovascular reflexes, and gastrointestinal (GI) symptoms were assessed by a detailed questionnaire. GE was assessed by electrical impedence tomography (EIT), at 2 hours after a standard semisolid meal. Mean half-time gastric emptying was significantly prolonged in diabetic patients, 54.80 ± 26.63 versus 40.37 ± 8.62 min (p < 0.05), with a higher prevalence in the first 3 years and after 10 years of disease duration. No differences were found between diabetics and controls regarding cardiovascular tests. No correlations were found between age, GI scores, cardiovascular tests, and GE. Patients with IDDM may suffer from prolonged GE. This is not always accompanied by autonomic impairments. As impaired gastric emptying may involve poor glycemic control and early satiety, patients with difficulties in metabolic control or poor caloric intake should be studied for the possibility of delayed gastric emptying.