An intensive survey of cultivated plants throughout the island of Montserrat resulted in the identification of a number of viruses. Squash mosaic virus was found in cantaloupe, pumpkin and squash. There were cases of multiple infection of pumpkin and squash by cucumber and squash mosaic viruses. Potato virus Y was recovered from pepper and tomato. Bean yellow mosaic and cowpea mosaic viruses were found in red kidney bean and string bean while cowpea mosaic virus was found in cowpea and broad bean (Jamaica bean). Other viruses that were previously identified on the basis of field symptomatology were confirmed by host range and serology. Viruses were not recovered from sea island cotton or from sweet potato, although field symptoms on the sweet potato are similar to those caused by sweet potato mosaic virus. The leaf tissues of crop plants were inoculated to a wide range of indicator plants. Some of those that reacted systemically were examined by electron microscopy for virus particles and the sap extracted from them was used in serodiagnostic assays for virus identification. This is the first attempt to identify positively the viruses of crop plants on the island.