Pulmonary arterial hypertension (PAH) is a progressive disease marked by increased pulmonary artery resistance leading to right heart failure with a high mortality. PAH is histologically characterized by endothelial and smooth muscle cell proliferation, medial hypertrophy, inflammation, and thrombosis in situ. Elevated pulmonary vascular resistance is the result of an imbalance between locally produced vasodilators and vasoconstrictors, in addition to vascular wall remodeling. Recent evidence demonstrates that inflammatory processes are involved in the generation of pulmonary vascular remodeling leading to PAH. Viral infections or similar immune-modulators trigger auto-antibody generation by endothelial injury and indirectly lead to PAH. All these immune-modulators associated with PAH, are also known to decrease the regulatory subgroups (CD4) of T cells. With a recognition of important role of inflammation in the development of PAH, anti-inflammatory agents and anti-cancer drugs are accepted as potential specific targets for PAH treatment. Though clinical studies are not enough, anti-inflammatory agents seem to be promising in the treatment of this devastating disease.