DAS‐ELISA was applied to the detection of cucumber mosaic cucumovirus (CMV) in tissues from olive trees of 25 cultivars in Portugal. The virus was detected in young leaves and roots of cuttings that had been hormone‐treated and subjected to rapid growth conditions in the glasshouse, and in fruits and leaves of field‐grown trees. Analysis by DAS‐ELISA of 222 samples revealed that approximately 10% were CMV‐infected and that some were also infected by another virus, strawberry latent ringspot nepovirus. The cultivars that were shown to be CMV‐positive were the following: Branquita, Cordovil de Serpa, Galega, Maçnilha Carrasquenha de Almendralejo, Maçnilha Fina, Madural, Negral de Calatayud, Negrinha, Picual and Redondil.