Virological investigations for herpes simplex virus (HSV), cytomegalovirus (CMV) and Epstein-Barr virus (EBV) were performed in nine patients of acute retinal inflammation. Serum samples of all the patients were assayed for IgG and IgM antibodies to HSV, CMV and EBV. Vitreous fluid (VF) from 5 patients was tested by immunofluorescence and culture for detection of HSV and CMV. In four patients, VF was also assayed for IgG and IgM antibodies to HSV and CMV. HSV was shown to be the etiological agent in 3 patients with acute retinal necrosis (ARN) syndrome and in one patient with multifocal retinitis. CMV was the causative agent in one patient of ARN and 1 patient with clinically diagnosed CMV retinitis. Evidences of infection with these three viral agents could not be obtained in one patient with clinical diagnosis of CMV retinitis who tested positive for antibody to human immunodeficiency virus 1. All other patients were HIV negative. Identification of the causative viral agent of acute retinal inflammations may help an ophthalmologist to institute specific therapy particularly for HSV and CMV infections.