Pulmonary arterial hypertension (PAH) is a progressive, fatal disease for which currently there is no curative therapy available. Pathologic changes in this disease involve excessive proliferation and migration of pulmonary artery smooth muscle cells (PASMCs). However, the underlying role of miR-150 in PASMCs remains elusive. Here in this study, miR-150 down-regulation was observed in hypoxia-treated PASMCs. Restoration of miR-150 attenuates hypoxia-treated PASMC proliferation and migration. Luciferase reporter assay showed that miR-150 directly regulated expression of HIF-1α. Moreover, overexpression of HIF-1α impaired the suppressive effect of miR-150 on the proliferative and migratory capacities of PASMCs. Altogether, our findings indicate that miR-150 may exert inhibitory effects on excessive proliferation and migration of PASMCs through down-regulation of HIF-1α, providing new insights into the potential mechanisms of human PAH.