A dot-immunobinding assay was adapted on enhanced chemiluminescence (DIBA-ECL), which employs luminol, a cyclic diacylhydrazide, as substrate for horseradish peroxidase conjugated with a secondary antibody, for the diagnosis of grapevine closteroviruses I and III. The sensitivity of DIBA-ECL was also compared to other immunoenzymatic methods. DIBA-ECL proved to be at least 16 times more sensitive than the dot-immunobinding assay using chloronaphthol/diaminobenzidine mixture as a substrate, which was at least twice as sensitive as DAS-ELISA, DAS-indirect avidin-biotin complex ELISA, and dot-immunobinding assay, using alkaline phosphatase as enzyme. Optimisation of all parameters involved in the DIBA-ECL procedure and its advantages are discussed.