In this study, the reactions of some potato cultivars and genotypes to Potato leafroll virus (PLRV) were evaluated in a field trial experiment. The experiment conducted as a randomized complete block design with 12 treatments and three replications. Each plot of the experimental design included a planting row of five potato plants of each cultivar/genotype. The experimental plants were then inoculated with the virus by putting 10 PLRV-carrying aphids, been raised on PLRV-infected potato plants, on each test plant. The acquisition (acquisition of the virus by the aphid vector was done on PLRV-infected potato plants) and the inoculation periods were 10 and 20 days, respectively. At the end of the inoculation period the aphid vectors were killed by spraying of an insecticide. One month after inoculation, the plants were examined for PLRV infection by observing symptom development and by using enzyme-linked immunosorbent assay (ELISA) test. The results revealed significant differences between the PLRV-infection rates of the potato cultivars/genotypes tested. The results of analysis of the data using SPSS soft ware also proved a significant correlation (79%) between the PLRV infection rates of the test plants based on symptom development and those of the ELISA tests. This relatively high correlation shows that using PLRV induced symptoms in potato, instead of ELISA test, is a suitable choice for determining the infection rate of test plants which, in turn, can save time and costs.