In a vineyard in Southern Portugal, the dominant spider species and their distribution on the plant were investigated. From the 19 spider families present, 61 species were identified, 4 of which were considered to be first records in Portugal. More than 90% of the spiders belonged to 10 species from 7 families. Most spiders were located on the lower surface of leaves, where leafhoppers fed. The predatory capacity of the spiders towards leafhoppers is discussed in the light of some ecological features.