The resistance to a Dideron isolate of Plum pox virus, which causes sharka disease, of four apricot (Prunus armeniaca L.) cultivars from North America (`Harlayne', `Henderson', `Sunglo', and `Veecot') and a Greek cultivar Lito (a cross of American cultivar Stark Early Orange × Greek cultivar Precoce Tirynthos) was evaluated. `Stark Early Orange' and `Canino', previously rated as resistant and susceptible respectively, were included as controls. Resistance, herein, was defined as inability to infect plants by graft-inoculation and negative assays by enzyme-linked immunosorbent assay. Cultivars found to be resistant were: `Harlayne', `Henderson', `Sunglo', `Lito', and `Stark Early Orange'. Cultivars Veecot and Canino were susceptible.