CA 125 and CA 15.3 serum levels were measured at diagnosis, after treatment and at the time of recurrence in 200 consecutive patients (114 males, median age 56 years) with non-Hodgkin's lymphoma (NHL) to explore its usefulness in the evaluation of response to treatment and survival in patients with NHL compared to lactate dehydrogense (LDH) and beta2-microglobulin (beta2-M). Their association with the clinical - biologic parameters at diagnosis, response to treatment, event-free survival (EFS) and overall survival (OS) was analysed. Eighty-six patients (43%) had elevated CA 125 levels and 35 (17.5%) had elevated CA 15.3 levels at diagnosis. CA 125 was associated with advanced stage, lung, pleural or gastrointestinal tract involvement and CA 15.3 was correlated with advanced stage, bone involvement, aggressive histology and bulky disease. LDH had the highest predictive value for failure to achieve complete remission (P = 0.001). A shorter OS was associated with increased LDH (P < 0.0001), beta2-M (P = 0.013) and CA 125 (P = 0.025) whereas CA 15.3 was associated with a shorter EFS (P = 0.027). When elevated at diagnosis, CA 125 and CA 15.3 should be monitored during follow-up of patients with NHL.