The aim of this study was to determine the seasonal population dynamics of spider mites [Panonychus ulmi (Koch), Amphitetranychus viennensis (Zacher), Bryobia rubrioculus (Scheuten)] and their natural enemies [Kampimodromus aberrans (Oudemans), Acari, Phytoseiidae; Zetzellia mali (Ewing), Acari, Stigmaeidae; and Stethorus punctillum Weise, Coleoptera, Coccinellidae] on Golden Delicious and Starking Delicious apple cultivars in three apple orchards of Van, Turkey, during 2002-2003. Surveys were carried out weekly from May to November in sprayed and unsprayed apple orchards. The results of study indicated that the population densities of spider mites began to increase generally in early May, reached the maximum level from mid June to late August and persisted until late September in both years. During 2002 the dominant species on both apple cultivars was P. ulmi, whereas in 2003 it was A. viennensis. In this two-year period, the population densities of P. ulmi and A. viennensis reached the maximum level of 318.1 and 427.2 mites per leaf, respectively, in sprayed orchards. In unsprayed orchard, spider mites remained at very low levels because of the presence of K. aberrans which was the only predator of spider mites. On the other hand, in sprayed orchards, although S. punctillum and Z. mali were the most abundant predatory species on spider mites, they could not control them in either apple cultivar and years.