Herbicides are now used throughout the globe and a majority of applied chemicals enter into the soil to form short or long-term residues, resulting in toxicity to sensitive crops and adverse effects on human and other life forms. Therefore, present work was undertaken to isolate and identify pyrazosulfuron-ethyl degrading fungi from soil of rice field. Alternaria alternata was isolated and identified from rhizosphere soil of rice field, as a potent pyrazosulfuron-ethyl degrading fungus and its degradation potential was evaluated under controlled conditions. In the soil pyrazosulfuron-ethyl was efficiently degraded by A. alternata. Degradation of pyrazosulfuron-ethyl by A. alternata was achieved by the cleavage of sulfonylurea bridge and hydrolysis. A. alternata used in the study can effectively be used for the enhanced degradation of pyrazosulfuron-ethyl in agricultural soil or mixed with other microbial consortia for rapid degradation with half life of 7.9 days.