Sixty-eight patients with a wide spectrum of brain pathology were imaged with both computed tomography (CT) using a G.E. 8800 scanner and nuclear magnetic resonance (NMR) imaging with a 3.5 kG prototype device. NMR was more advantageous in the detection and/or characterization of pathology in 20 of the 68 patients, especially when demyelination was part of the disease process or when the lesion was obscured on CT by beam-hardening artifact. Punctate foci of calcification identified on CT were not detected on NMR, but larger calcifications were seen. NMR was sensitive to detection of both normal and abnormal vascular structures. The ability of NMR to differentiate among different pathologic entities remains to be fully evaluated. NMR currently complements CT in the evaluation of many disease entities and may actually supplant CT in some. The full future potential of NMR and its role with respect to CT has only begun to be elucidated.