Infantile capillary hemangiomas are vascular neoplasms that can appear quite infiltrative histologically and that are characterized by cords of cells with areas of marked cellularity. These lesions have been shown to contain a population of rapidly proliferative endothelial cells. Given the recent association between the presence of human herpes virus 8 (HHV8) and another proliferative vascular lesion, Kaposi's sarcoma, we used polymerase chain reaction technology to examine a series of 16 biopsy specimens from 15 infantile capillary hemangiomas for the presence of HHV8 DNA. We were unable to detect HHV8 DNA in any of the lesions studied. All of the cases were examined in parallel with a case of Kaposi's sarcoma that was known to be positive for HHV8 DNA and a series of negative controls. In all of our cases, amplification of beta-globin gene DNA demonstrated adequate preservation of DNA in the tissue studied. These findings suggest that not all endothelial cell proliferations can be attributed to HHV8 and that the etiology of some of these conditions remains unclear.