The relation between body mass (BMI) and soft-tissue sarcoma (STS) risk was evaluated in a case-control study from Northern Italy based on 217 incident STS and 1297 hospital controls. The risk of STS rose with BMI, with multivariate odds ratios of 3.49 (95% confidence interval (CI) 1.06-11.55) among men and 3.26 (95% CI 1.27-8.35) among women with a BMI > 30 kg m(-2) compared to those with BMI < or = 20 kg m(-2).