The usefulness of 99mTc-labeled RBC single photon emission CT (SPECT) scanning in the diag- nosis of hepatic heminagiomas was evaluated in 22patients with various focal hepatic lesions including 15 cases of hemangiomas, 3 cases each of hepatomas and rnetastasis and 1 case of abscess. The diagnoses were based on ultrasonography and/or CT scanning, clinical stability of lesion for at least 6 months or surgical exploration. Seven cases of 1S hemangiomas were detected by delayed planar RRC scanning, whereas 4 cases were detected by delayed RBC-SPECT scanning. The smallest hemangioma shown hy delayed RBC-SPECT scanning was 1.0 cm m diameter, compared with 2,2 cm by planar RBC scanning. One smaIl hemangioma (2 0 cm) located adjacent to the heart was not found by either method. The sensitivities in detecting the hemangioma according to the size by planar imaging were 16.6% (l.0 1.9 cm), 66. 7% (2.0 2.9 cm) and 83.3% (more than 3.0 cm) and by SPECT were 50.0%, 66.7% and 100%, respectiively Seven cases of non-hemangiomatous Iesions did not show any significant increase in activity in the delayed blood pool images. It is concluded that 99mTc-RBC blood-pool SPECT scanning is clearly more sensitive in detecting small hemangioma than planar scanning and is, therefore, a choice of method for the detection of hepatic hemangiorna.