Seventy-four consecutive previously untreated patients with Hodgkin's disease (HD) and non-Hodgkin lymphomas (NHL) were evaluated with chest, abdominal and pelvic magnetic resonance (MRI) for initial staging. All patients underwent routine radiological staging procedures which included chest radiographs and lymphography (LAG). These studies were followed in most of cases by laparoscopy, during which biopsies of the liver and the spleen were taken, and bone marrow aspiration and histology. A correlation of the results of MRI with both other imaging studies and histopathologic diagnoses was performed, and discordant cases were assessed to determine the impact on clinical staging. Additional evidence of disease involvement was provided mainly in the chest, where MRI demonstrated the presence of unsuspected disease in 21% of involved patients (9 of 42). Retroperitoneal lymph nodes were correctly assessed in 97% of cases if MRI was compared with LAG. Extranodal abdominal disease was identified both in the spleen (14%) and in the liver (1%). Bone marrow abnormalities were detected in 19% of patients (14 of 74). MRI findings influenced the staging of HD and NHL patients in 11 of 74 cases (15%).