Background: The purpose of this study was to evaluate the effect of weight changes after completion of chemotherapy on the prognosis and survival of patients with intermediate and high grade non-Hodgkin's lymphoma. Materials and Methods: A retrospective analysis of data on patients fr om the TCOG T1488 protocol, a phase II study using CHOP in the treatment of intermediate and high grade lymphoma. From September, 1988 to December 1994, 138 adult patients had complete weight data for analysis. Weight gain in lymphoma patients after therapy, significantly correlated with improved survival (Logrank test p =. 0031). In patients with initial B symptoms, weight gain after therapy, correlated with survival (Logrank test p =. 0039), female patients (odds ratio=6.2) were less likely to gain weight on treatment. Conclusion: Weight gain after chemotherapy for lymphoma is a significant positive prognostic factor for survival.