In vitro safety studies of thiamethoxam to Trichogrammapretiosum (Riley) was conducted at the Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore during 2014. Field recommended doses of thiamethoxam 25 WG viz., 25, 50, 75,100 g a.i./ha were evaluated for their effects on parasitization and emergence. These revealed that the recommended dose @ 25 g a.i./ ha resulted in 93.00% adult emergence and 77.96% parasitization, and all these doses did not adversely affect T. pretiosum