PURPOSE: To evaluate the usefulness of ultrasonography in the diagnosis of local recurrent soft tissue tumors. MATERIALS AND METHODS: We retrospectively analysed the results of 113 sonographic examinations in 102 patients (38males, 64 females) after surgical treatment of soft tissue tumors (82 malignancies, 20 benignancies) during thelast five years. Follow-up included physical and sonographic examinations using a 5-10MHz transducer every twomonths. In 17 cases, MR images were obtained The criterion for local recurrence was discrete mass, and size,shape, margin, echogenicity, and homogeneity were also analysed. Forty-one patients underwent surgery. RESULTS: Among 113 cases, 41 local recurrences were proven by surgery and histological analysis; well-defined, ovoid,homogeneous hypoechoic masses of various sizes were apparent. Sonographic sensitivity and specificity were both97%. MR sensitivity and specificity were 83% and 100% respectively, but in most cases in which MR had been usedthe masses were greater than 3cm in diameter. Two cases were false positive; these were thought to be granulomas,but were shown during follow-up lasting 36 and 14 months, respectively, to be unchanged hypoechoic nodules. Onecase was false negative. CONCLUSION: For the diagnosis of local recurrent soft tissue tumors, ultrasonography isvery useful. For early detcction, it is superior to MR imaging.