Technical Abstract: Contamination of surface waters by pesticides is a growing concern in the United States and around the world. Innovative mitigation strategies are needed to remediate this potential environmental contaminant. One potential solution is diverting pesticide-laden drainage or surface water through post-harvest agricultural rice fields. With a hydroperiod, hydrosoil, and hydrophyte (rice stalk), these systems serve essentially as a type of constructed wetland. In both a summer and fall experiment, diazinon-amended water was diverted through two rice ponds at the University of Mississippi Field Station. Likewise, a non-vegetated control pond was amended with diazinon-laden water. Water, sediment, and plant samples were taken spatially and temporally to determine the distribution of diazinon within systems. Outflow diazinon concentrations were significantly (p<0.05) decreased from inflow in both vegetated ponds for both pre-harvest and post-harvest experiments. Although sorption to rice plants was minimal in the overall mass distribution of diazinon (1 – 3%), temporal data indicated diazinon concentrations reached the outflow sediment of the non-vegetated control twice as fast as in either vegetated (rice) system. In both vegetated systems, sediment diazinon concentrations decreased (77% and 100%) from inflow to outflow, while a decrease of < 2% was noted in the non-vegetated control. Diversion of pesticide contaminated water through post-harvest rice fields demonstrated potential as a low-cost, environmentally efficient mitigation practice. Studies on these systems are continuing to evaluate the optimal chemical retention time for rice field mitigation.