The management and understanding of pulmonary arterial hypertension (PAH) has undergone something of a revolution in the last 10 years, with new pharmacological agents entering routine clinical practice and significantly improving outcomes. Nevertheless many patients ultimately progress, and additional new treatment approaches are needed. There is now greater understanding of the molecular and genetic basis for the development of PAH, specifically in regard to the role of bone morphogenetic protein receptor 2 (BMPR2) signaling and related pathways. The challenge is to determine whether these new discoveries can be exploited for new therapies. In this article the role of viruses as tools for gene delivery for pulmonary vascular disease is discussed. Gene delivery of BMPR2 has now been shown to ameliorate the development and progression of PAH in animal models, thereby identifying this approach as a therapeutic target.