New Findings• What is the Topic of this review? This review summarises our current knowledge of dysregulated bone morphogenetic protein (BMP) and transforming growth factor‐β1 (TGFβ1) signalling in pulmonary arterial hypertension. • What advances does it highlight? Reduced expression of the bone morphogenetic protein (BMP) type II receptor is common to the monocrotaline (MCT‐PAH) and hypoxic rat models of pulmonary hypertension (PH). However, reduced BMP signalling and enhanced transforming growth factor‐β1 (TGFβ1) signalling is observed only in MCT‐PAH. Furthermore, TGFβ1 receptor blockade blocks MCT‐PAH, but not hypoxic PH. Transforming growth factor‐β1 inhibits BMP signalling in pulmonary artery smooth muscle cells.