Scintiangiography of xiphopagus conjoined twins following sequential i.v. injection of Tc-99m sulfur colloid revealed the size, configuration, and anatomic point of fusion of the twins' common liver prior to surgery. Cross circulation was determined to be non-significant by this approach. The technique is presented, compared to other methods, and the benefit of sequential hepatic scintiangiography for xiphopagus conjoined twins is reviewed.