The results of field experiments showed that an improved crop package caused considerable reduction in density and dry weights of all categories of weeds and increased yield four times over traditional farmers’ practices in rainfed upland rice. Better land preparation (two ploughings at 15 d.b.s. and two at sowing), timely sowing (last week of June), application of fertilizer and an additional hand weeding markedly decreased the infestation of all categories of weeds in rainfed upland rice and helped in producing high grain yield. Improved variety and organic manuring had no effect on weed infestation but seemed to be essential for the yield improvement of upland rice.