OBJECTIVE To ascertain in real practice the diagnosis rate of diabetic retinopathy (DR) in patients considered to have positive screening test by general practitioners (GPs) and what are the reasons for the false positive diagnosis. METHODS Four GPs previously instructed in the interpretation of retinal photographs evaluated the digital retinography images of patients with diabetes obtained during a 2-year period. When the images were considered normal, a new appointment was scheduled for 1 year later and a report was emailed to the referring physician. Patients with any sign of DR or other suspicious retinal alterations and those whose images were considered difficult or impossible to assess were referred to an ophthalmologist. RESULTS A total of 2750 patients were referred for screening. The images of 2036 (74%) patients were considered normal, and the images of 714 (26%) patients were sent to ophthalmologists. Among the referred patients, 392 (55%) did not have DR, 244 (34%) had DR, and 78 (11%) had unreadable images. The retinal images of 240 patients whose fundi were considered normal were read again by ophthalmologists to evaluate false negatives. Of them, 16 patients (7%) had DR but only two patients (1%) had treatable DR. CONCLUSIONS After adequate training, GPs can screen for DR with a high level of accuracy using non-mydriatic retinography. There is a need to strengthen the training of GPs in order to recognize non-visual threatening abnormalities.