Temperature is one of the main factors of crop production and it influences herbicide persistence by affecting different herbicide degradation reactions in the soil. To study the persistence of trifluralin and imazethapyr affected by different temperature regimes, an experiment was carried out under lab and screen house conditions at CCSHAU, Hisar. Bioassay technique was used to quantify the persistence by employing sensitive plants of oat and mustard for trifluralin and imazethapyr bioassay, respectively. Soil treated with these herbicides at different rates (trifluralin 0.0, 0.125, 0.25, 0.5, 1.0 and 2.0 kg/ha and imazethapyr 0, 10, 20, 40, 80 and 160 g/ha) after incubation at 15, 25, 35 and 45OC temperature regimes in incubator. Persistence of herbicides affected by different temperature regimes at different herbicide rates was measured by comparing shoot and root growth, fresh and dry weight with control treatment, at different intervals. With increase in incubation temperature of different imazethapyr rates; all growth parameters of mustard except germination, increased, indicating that the increased temperature showed decreased persistence of imazethapyr, with minimum persistence between 35 and 45OC. Whereas trifluralin showed minimum persistence at 25OC and maximum at 15OC as revealed by different growth parameters of oat. In both the herbicides, different growth parameters of test plant decreased with increase in herbicide rate at different temperature incubations pointing that there was increased persistence with increased herbicide rates.