Tumor cytogenetic analysis was done for 68 patients with newly diagnosed non-Hodgkin lymphoma, and recurring cytogenetic abnormalities were correlated with achievement of complete remission, duration of complete remission, and survival. Among all patients, the presence of normal metaphases in tumor material was associated with a higher complete remission rate and longer survival. However, the duration of complete remission did not correlate with the presence or absence of chromosomal changes. Among patients with follicular lymphomas, the presence of normal metaphases in the tumor material was again associated with a higher rate of complete remission and with longer survival. Patients with structural abnormalities of chromosome 17 had a shorter survival than patients without these abnormalities. Among the patients with diffuse large-cell and immunoblastic lymphomas, those with breaks in the short arm of chromosome 2 had a longer survival than those without these breaks. We conclude that chromosomal abnormalities are predictive of clinical outcome in malignant lymphoma.