We studied the prevalence of sleep disturbances in 184 persons with diabetes, and 99 controls matched for age and sex. Sleep disorders were more common in diabetics (33.7% vs. 8.2% in controls; P < 0.01). Patients with sleep disturbances were younger than those with normal sleep, and had onset of diabetes at a younger age. There was a significant association of sleep disturbances with the presence of cough, dyspnea, nocturnal cramps, paresthesia and burning of soles. Sleep disturbances may be due to physical discomfort, psychosocial factors, fluctuations in metabolic control and perhaps also hypoinsulinemia. Quality of life is affected and coping with the disease is made difficult by sleep disorders. Thus, physicians caring for persons with diabetes must be able to recognize, diagnose and manage sleep disturbances in their patients, when they occur.