The total cavopulmonary bypass (TCPC) is a surgical intervention which attempts to provide a satisfactory pulmonary blood flow when the right heart can not sustain it, due to congenital or acquired diseases. In a TCPC, the venae cavae are anastomosed to the pulmonary arteries, with a typical hemodynamics. The authors' study is aimed at the quantitative investigation of the flow field through a TCPC, by means of a glassblown replica and the application of the particle image velocimetry technique. Different loading conditions, representative of realistic in vivo conditions, were set, in order to study how this connection reacts to changes in haemodynamics.