Decellularized allograft heart valves have been used as tissue-engineered heart valve (TEHV) scaffolds with promising results; however, little is known about the cellular mechanisms underlying TEHV neotissue formation. To better understand this phenomenon, we developed a murine model of decellularized pulmonary heart valve transplantation using a hemodynamically unloaded heart transplant model. Furthermore, because the hemodynamics of blood flow through a heart valve may influence morphology and subsequent function, we describe a modified loaded heterotopic heart transplant model that led to an increase in blood flow through the pulmonary valve. We report host cell infiltration and endothelialization of implanted decellularized pulmonary valves (dPV) and provide an experimental approach for the study of TEHVs using mouse models.