Primary dysfunction (PDF) and eventual primary nonfunction (PNF) of liver allografts have been characterized by various clinical and laboratory parameters reflecting graft function, cellular integrity and extrahepatic influence following orthotopic liver transplantation (OLT). During the past 6 yr we have been able to demonstrate that this potentially devastating condition is routinely accompanied by a pathological initial perfusion pattern detected by colour flow doppler imaging (CFDI) within hours following OLT. In the majority of PDF cases (n = 30) CFDI revealed increased vascular resistance in regard to arterial blood flow to the malfunctioning graft, with a resulting 1-yr graft survival rate of 80% following the institution of early prostaglandin therapy in this group of patients. A completely different perfusion pattern was noticed by CFDI in a total of 13 cases with grossly decreased arterial resistance, resulting in an apparently supranormal arterial blood supply together with a reduced portal inflow in comparison to primarily functioning grafts. The presence of this pathologic graft perfusion was explained by the formation of arterio-portal shunts within the graft during conservation and reperfusion, leading to a 1-yr graft survival of merely 46.1%.