To detect cucumber mosaic virus (CMV), virus samples and conjugate were incubated together in a simplified double-antibody sandwich ELISA. The use of the same monoclonal antibody (MAb) as trapping (coating) and detecting antibodies resulted in considerable decrease of ELISA values and sensitivity due to the competition for antigen between trapping and detecting antibodies. The simplified ELISA using two MAbs which recognize different epitopes of CMV proved to be a rapid and sensitive method for virus detection.