Greenhouse experiments were conducted in the Fall of 2010 and Spring of 2011 to determine the effectiveness of single and combined releases of Turkish populations of two predatory mite species, Phytoseiulus persimilis Athias-Henriot and Neoseiulus californicus (McGregor), for control of two spotted spider mite (red form) (Tetranychus urticae Koch) on eggplant. The same number of predators was released into cages in a greenhouse with similar numbers of spider mites. The control treatment had significantly higher numbers of T. urticae in both years except for 2010 when the N. californicus single treatment was not different. Among the predator release treatments, the lowest total mean number of T. urticae was found in the P. persimilis single releases in both seasons. These means were followed by the combined predatory mite and the N. californicus single release in 2011. In both years, P. persimilis numbers in both the single and combined treatments were significantly higher than the numbers of N. californicus, except in the N. californicus single treatment in 2011. Overall, releasing N. californicus either alone or in combination with P. persimilis did not show any improvement in controlling to T. urticae on greenhouse eggplant when compared to the release of P. persimilis alone.