In this study, the success of single and combined releases of Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) and Macrolophus melanotoma (Costa) (Hemiptera: Miridae) aganist Bemisia tabaci (Gennadius) (Hemiptera: (Aleyrodidae) were determined on greenhouse grown tomato plants that planted in net cages. The studies were conducted in spring growing seasons of the years 2009 and 2010. Experiments were established with four different treatments namely B. tabaci single (control), M. melanotoma single, E. mundus single, M. melanotoma+E. mundus combined releases with 3 replications (cage). In both years the B. tabaci, E. mundus and M. melanotoma were released 20, 6 and 0.5/plants, respectively. In order to determine population development of B. tabaci and E. mundus, leaf samples were taken at weekly intervals. In addition, numbers of immature and adult stages of M. melanotoma were counted by using visual control method on whole parts of 15 plants in each predator released cages. In the parasitoids released cages, the mean numbers of immature B. tabaci were not reached higher than 0.56 and 2.82 individuals/cm(2) in 2009 and 2010, respectively. These numbers were found to be lower than control and M. melanotoma single releases. The highest immature B. tabaci numbers were determined in control treatments as 51.10 and 31.12 per cm(2) in both years. Although M. melanotoma single release treatment reduced the whitefly numbers statistically compared to control treatment, it was not succeed as much as E. mundus. The results of this study showed that B. tabaci populations could be control without any insecticide treatments in greenhouse by using biological control programs that will be consisted with E. mundus and M. melantoma in Turkey.