This research was performed in order to study and diagnose Potato virus Y, Potyvirus (PVY), Potato virus X, Potexvirus (PVX), Potato virus S, Carlavirus (PVS), Potato virus A, Potyvirus (PVA) and Potato leaf roll Luteo virus (PLRV) on tubers and leaves of different potato varieties, namely, Solea, Safran, Floris, Proventa, Milva, Universa, Lady olympia, Vangogh, and Marabel grown in Afyon region of Turkey. For this purpose, potato tubers from different varieties were obtained from Afyon region producers during 2009-2010 and they were planted in the trial plots in Isparta region of Turkey. One hundred sixty nine samples were taken from the leaves showing virus symptoms in the vegetation period and 109 samples were taken from the tubers of suspicious plants in the harvest period. Total of 278 samples were tested by using double antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA) method. The DAS-ELISA analysis revealed that both tubers and leaves were infected with PVY, PVX, PVS, PVA and PLRV. It was determined that 87.45% (244 samples) of the tested samples were infected with one or more viruses and 12.54% (34 samples) of them gave negative reaction with DAS-ELISA. Regarding the prevalence of viruses among the potato varieties in this study, it was found that all samples belonging to Safrane and Milva varieties were infected with one or more viruses. Besides, other potato varieties showed different rates of virus infection. In the mechanical inoculation tests, serious stunting, systemic chlorosis and leaf deformation symptoms were observed on N. glutinosa, while symptoms such as mottling, leaf distortion, chlorotic and necrotic local lesions were observed on the leaves of other test plants.