A factorial experiment, based on RCB design, with three replications was conducted to evaluate the effects of rhizobial inoculation, urea, and weeds on soybean performance in the field. The factors under study consisted of inoculation and non-inoculation, three levels of 0, 150, and 300 kg/ha urea, and weed-control and weed-infestation. Results showed that weed-control, inoculation and urea application increased biological and seed yield. The highest effect on yield was due to weed control, followed by inoculation and urea application. Inoculation, weed-control and urea application of 300 kg/ha enhanced protein percentage in soybean grains. In this case, inoculation had the highest effect on protein percentage, followed by urea application and weed control. In contrast, only weed-control significantly increased seed oil percentage. Seed filling rate increased as a result of inoculation, but, seed filling duration was not affected by inoculation. Weed-control improved seed filling rate and duration. Urea application induced seed filling duration, but had not any effect on seed filling rate.