Cytokines play important roles in the pathogenesis of lymphomas. This study aimed to determine the relationship(s) between serum levels of interleukin (IL)-6, IL-8 and IL-10, measured by enzyme-immunoassay, and the clinical characteristics and outcomes in 46 untreated patients with diffuse large B-cell lymphoma (DLBCL). Serum IL-6, IL-8 and IL-10 levels were higher in DLBCL patients than in control subjects. Elevated levels of IL-6, IL-8 and IL-10 correlated with more adverse disease features. Consequently, patients with elevated IL-6, IL-8 and IL-10 levels prior to treatment had a lower response to therapy. Furthermore, those with elevated IL-6 and IL-10 levels had poor median, 3-year and 5-year survival, while elevated serum IL-8 level did not correlate with overall survival. Worse survival was also confirmed in patients with combined elevated pretreatment serum levels of IL-6, IL-8 and IL-10 (none, one, two or three elevated). Multivariate analysis identified elevated values of IL-6 and IL-10 and response to therapy as significant predictors for overall survival. Serum levels of IL-6, IL-8 and IL-10 before treatment of patients with newly diagnosed DLBCL may give some insight into the possible prognosis and thus facilitate the decisions regarding therapeutic approaches for individual patients.