Study investigates the diversity, distribution, and ecological characteristics of weed species around Napasar, region of Bikaner Rajasthan. Weeds plants are grown undesirably where they have affected agricultural productivity, alter the native biodiversity, and influence habitat conditions. The present research, conducted during 2024–25, employed stratified field surveys across representative habitats within the Napasar region: agricultural fields (rainfed and irrigated), roadside margins, fallow lands, urban vacant lots, and canal banks. Major families included Poaceae, Asteraceae, Fabaceae, Amaranthaceae, and Chenopodiaceae. The study emphasis that the diversity index ranged from low in intensively managed irrigated fields to higher values in fallow and roadside habitats, indicating that management practices and disturbance regimes strongly influence weed assemblages. Several species identified are major agronomic weeds (e.g., Cynodon dactylon, Chenopodium album, Alternanthera sessilis), while others are emerging invasive or spreading taxa. The findings provides baseline data for weed management strategies tailored to Napasar semi-arid agro-ecosystems and can inform conservation planning where weeds threaten native plant communities. The research aims to produce practical recommendations for integrated weed management tailored to the local socioecological context.