The roles of single-photon emission computed tomography (SPECT) and planar imaging with technetium-99m-labeled red blood cells in the diagnosis of cavernous hemangioma of the liver were evaluated. The study group consisted of 26 consecutive patients referred for evaluation of liver lesions. A total of 23 cavernous hemangiomas were found, all of which showed decreased or normal flow and delayed uptake of the radiotracer. SPECT demonstrated 13 hemangiomas that were not detected with planar imaging; both modalities demonstrated the other ten lesions. Lesions that were not cavernous hemangiomas showed either normal (n = 6) or increased (n = 4) flow; none had delayed increased uptake on either planar or SPECT images. SPECT with labeled red blood cells is an accurate method for the detection of cavernous hemangiomas of the liver and is more sensitive than planar imaging in depicting small lesions.