In-house developed ELISA was standardized to monitor atrazine residues in different environmental samples. The standard curve was linear, indicating an increase in log concentration with decrease in absorbance (%B/B(0)=1.075-0.042 Log C; r= -0.966). The middle of the test was at 75 ng/L and the lowest detection limit at 4 ng/L. ELISA significantly correlated with the high performance liquid chromatography (HPLC) (r=0.990). Internal validation showed good accuracy and precision. Maximum atrazine residues were present in Jehlum River water/sediments and maize/sugarcane plant roots. Most of the food samples were found to be contaminated. ELISA required less clean-up steps than HPLC, but showed matrix effect in soil/colored extracts.