Serum levels of sICAM-1, sIL-2alphaR, and beta-2 microglobulin were measured in 63 patients with non-Hodgkin's lymphoma (NHL). The correlation between these serum markers as well as their relationship with NHL features and disease outcome were analyzed. Although in high-grade NHL sICAM-1 levels correlated with tumor mass, no correlation was found between sICAM-1 levels and tumor burden in low-grade NHL. When compared with sICAM-1 and beta-2 microglobulin, sIL-2alphaR showed the strongest correlation with the tumor burden. However, in multivariate analysis, including serum markers employed as continuous variables, the only parameteres which entered the regression model were beta-2 microglobulin (p=0.012) and sICAM-1 (p=0.019). In a dichotomized model, beta-2 microglobulin, aggressive histology, sICAM-1, age and number of nodal involved sites were found to be prognostically significant. Finally, by combining sICAM-1 and beta-2 microglobulin serum levels, a simple prognostic model useful for NHL was obtained.