Twenty-three consecutive patients with Waldenström macroglobulinemia were studied with magnetic resonance (MR) imaging of the spine and computed tomography (CT) of the abdomen and pelvis. MR imaging studies included sagittal T1-weighted and gradient-recalled-echo sequences performed with and without contrast material enhancement. Marrow involvement was identified with MR imaging in 21 of 23 (91%) patients. Diffuse involvement was noted in 13 patients (56%), and a variegated pattern in eight (35%). CT demonstrated enlarged nodes in 10 of 23 (43%) patients. Correlation of MR imaging patterns and presence of adenopathy at CT with standard laboratory values for Waldenström macroglobulinemia revealed an association of the diffuse MR imaging pattern of marrow involvement and the presence of enlarged nodes at CT with more advanced disease. MR imaging of the spine and CT are reliable means of evaluation of disease status in Waldenström macroglobulinemia. They may be employed as additional means in the staging of Waldenström macroglobulinemia and may be helpful in the follow-up of patients with this rare hematologic malignancy.