Soft tissue sarcomas are rare tumors with a high risk or local recurrence and a risk of distant metastases. Standard treatment advocated is the combination of conservative resection and external radiotherapy. Brachytherapy is an integrated part of the multidisciplinary treatment. Brachytherapy can increase local control with good functional results. Primary exclusive brachytherapy has been used and is effective and safe in high grade sarcomas (randomized trial of MSKCC). Brachytherapy seems to be important as part of the treatment of central localization (shoulder, groin) and sarcomas with positive resection margins, but its relation with external radiotherapy has to be defined. Brachytherapy used with special guidelines allows to obtain an improved local control with an acceptable level of complication.