Seven spider mite species were recorded for the first time in Serbia: Bryobia macedonicaHatzinikolis & Panou, 1996 and Bryobia querciHatzinikolis & Panou, 1997 from Bryobiinae, and Eutetranychus orientalis Klein, 1936; Oligonychus bicolor Banks, 1894; Oligonychus platani McGregor, 1950 Tetranychus canadensis McGregor, 1950 and Tetranychus ludeni Zacher, 1913 from Tetranychinae. Together with previously reported data, these findings raise the number of known tetranychid species in Serbia to 44, the second highest number of spider mite species recorded in the Balkan countries. The records of O. bicolor and T. canadensis are also the first ones on the Balkan Peninsula. The most frequent species were T. ludeni and E. orientalis, found in 24 and 13 out of 57 sampling locations. Spider mites were recorded on host plants in four basic habitat types, but predominantly in cultivated habitats and woodlands. A total of 27 plant species from nine families were recorded as hosts for newly recorded spider mites, including 12 plant species as new hosts for four tetranychids, and three plant species as new hosts for the family Tetranychidae. Plant family Rosaceae had the highest number of new hosts (7) and harbored the highest number of spider mite species (5). Tetranychus ludeni had the highest number of host plants (11) with two plant species as its new hosts. Oligonychus bicolor was found on eight host plants including five new hosts for this species and one new host for the family Tetranychidae. The other two new hosts for the family Tetranychidae harbored O. platani and B. querci, respectively. Symptoms of heavy infestations by E. orientalis and T. ludeni were recorded on host plants in several locations.