To obtain data on the main species of phytoseiid mites occurring at Regiao Demarcada do Douro (RDD), Portugal, a survey was carried out from late July to early August 1997 in 61 vineyards, comprising 41 unsprayed and 20 sprayed vineyards according to the usual practices in the region. From the unsprayed vineyards, 18 were situated in the north region of the Douro river and 23 were located in the south region of this river. The sprayed vineyards were all situated in the north region of the Douro. Sampling was done on 20 random selected leaves from 5 plants in each vineyard, and phytoseiids were extracted and identified. Seven species were found: Euseius finlandicus (Oudemans), E. stipulatus (Athias-Henriot), Kampimodromus aberrans (Oudemans), Neoseiulus californicus (McGregor), Typhlodromus athenas Swirski and Ragusa, T. phialatus Athias-Henriot and T. pyri Scheuten. The dominant species were T. pyri and K. aberrans. T. pyri, which represented 47.2% of total number of individuals, were found mostly in the South region of Douro in cooler sites. K. aberrans, which represented 46.7% of the total number of individuals, dominated in the North region of Douro, in warmer and drier places. T. phialatus and T. athenas were common in the sprayed vineyards. The dominant species of phytoseiids found in the region, T. pyri and K. aberrans, were known as the most efficient agents against spider mites in many vine-growing areas of Europe.