Purpose: To investigate the efficacy and toxicity of postoperative intensity-modulated radiation therapy (IMRT) for patients with soft tissue sarcomas (STSs) in the extremities and trunk wall.Patients and methods: Eighty patients with localized STSs in the extremities and trunk wall treated with function-conserving surgery and postoperative IMRT were analyzed.The primary locations were in the extremities in 51 patients and in the trunk wall in 29 patients.The margins were positive in nine patients and negative in 71 patients.The median dose of IMRT was 64 Gy.Results: At a median follow-up time of 38 months, eight patients developed local recurrences.The 5-year local control (LC) rate was 88.1%.The patients with negative margins exhibited much better LC than did those with positive margins (90% vs 64.8%, P=0.023).Multivariate analysis revealed that positive margin was an independent risk factor for LC.The 5-year distant metastasis-free survival, disease-free survival, and overall survival rates were 75.2%, 72.6%,and 83.6%, respectively.Large tumor size (>5 cm) was significantlyassociated with poor overall survival.Edema and joint stiffness were observed in 17.6% and 9.8% of patients with extremity STSs, respectively.Conclusion: IMRT provides excellent LC and low toxicity for patients with STSs in the extremities and trunk wall.