Abstract: The objectives of this study were to determine the effects of weed infestation on seed yield and yield components of double-cropped soybean and to determine critical time of weed removal after emerging that double-cropped soybean can tolerate before yields are reduced. Eleven weed duration periods were created by removing weeds by weekly intervals after emergence. Plants grown in different weed duration plots were examined and compared with weedy and weed-free controls. The experimental design was Randomized Complete Blocks with three replications. Plants grown in weedy control plots had taller plant heights than weed-free control and the other weedy plots. Branch number, node number, pod number and seed number per plant decreased when the duration of weed infestation increased. Maximum soybean seed yield was obtained when plots were kept weed-free, followed by weedy 1 Week After Emerging (WAE). In weedy control plots, seed yield was reduced. The result of present study showed that 1-week delay in removing of weeds significantly reduces seed yield in double-cropped soybean.