Field and laboratory experiments were conducted to study the persistence and dissipation of pretilachlor in soil, straw and flood water. In soil, pretilachlor at 0.75 kg/ha dissipated to below detectable level (BDL) within 30 days after application (DAA) when applied along with green leaf manure, while in other treatments viz., pretilachlor at 0.75, 1.5 kg/ha alone and gypsum + pretilachlor at 1.5 kg/ha persisted up to 45 DAA (DAA). In the case of plant, pretilachlor at 0.75 kg/ha dissipated to below detectable limit at 30 DAA, while 1.5 kg/ha persisted up to 60 DAA. Irrespective of the treatments, pretilachlor dissipated to below detectable limit at 10 DAA in flood water. The half-life of pretilachlor varied from 3.9-10.0, 3.4- 8.5, 0.87-1.52 days for soil, rice plant and flood water, respectively.