Two hundred sixty-seven patients with high-grade (G2,G3) soft tissue sarcomas but without distant metastases, were studied retrospectively with respect to their duration of symptoms and size of tumor. Prognosis was significantly related to the size of the tumor (P = 0.0039). Small tumors (5 cm or less) had a 5-year survival rate of 49% compared to 28% for large tumors (more than 5 cm in diameter). Symptom duration was not related significantly to survival time (P = 0.2490). The ratio of the size of the tumor (greatest diameter, recorded in cm) to duration of symptoms (recorded in months), reflecting the growth rate of the tumor, is introduced as a potentially important prognostic variable. Analysis revealed a highly significant relation between an increasing size/duration ratio and shorter overall survival time (P less than 0.0001) and time to distant metastases (P = 0.0034). Moreover, an optimal cut-off point of 1.0 for the size/duration ratio offers prognostic information independent of the G-TNM classification and other prognostic factors.