To compare the diagnostic properties of a nonmydriatic 200 degrees ultra-widefield scanning laser ophthalmoscope (SLO) versus onsite mydriatic ophthalmologic examination for diabetic retinopathy. A consecutive series of 51 eyes of 51 patients with different levels of diabetic retinopathy (DR) was examined. Grading of diabetic retinopathy and macular edema obtained on stereoscopic dilated funduscopy by a retina specialist was compared against grading obtained from Optomap Panoramic200 SLO images. All SLOs were performed with an undilated pupil, and no additional clinical information was used for evaluation of the Optomap images by three independent, masked expert graders. A total of five images (9.8%) were not gradable due to insufficient quality. Clinically 4 eyes had proliferative diabetic retinopathy (PDR), while 9 had none, 5 mild, 19 moderate and 14 severe nonproliferative diseases (NPDR). Of the gradable 46 images, a clinically significant macular edema (CSME) was present in 28 eyes clinically. On Optomap, all eyes with PDR were detected as being proliferative, and a sensitivity of 94% at a specificity of 100% was obtained for all graders to detect more than mild DR. Agreement between Optomap retinopathy grading and clinical assessment was good with unweighted kappas of 0.68, 0.68 and 0.51. Assessment of CSME yielded sensitivities of 93, 93 and 89% at specificities of 89, 72 and 83%. The Optomap Panoramic200 nonmydriatic images are of sufficient quality to assess DR and CSME validly and therefore fulfill the basic requirements for telescreening programs.