Combined A- and B-scan examination of eyes with diabetic retinopathy and opaque media provides information about the presence and density of vitreous hemorrhages, can detect membranes inserting into the optic disc or the retina and differentiate them from retinal detachment. Absolute and relative indications for echographic examination are listed and some echograms concerning vitreous hemorrhage, proliferating membranes and traction retinal detachment are presented. The value of both A-scan standardized echography and contact B-scan technique for previtrectomy evaluation is stressed.