Idiopathic Pulmonary Arterial Hypertension (IPAH) is a subset of cardiovasculardisease, and the most neglected from the public point of view. Estimation of diseaseprevalence becomes difficult in the developing world because of economic,ethnic, socio-cultural and geographic diversity. Several patients may not reach centers equipped with diagnosing PAH, thus, only a small portion of the patients with the disease are captured in disease registries. Female predilection is commonly seen in IPAH with the female to male ratio ranging from 2:1 to 9:1. Clinical characteristics of IPAH patients in the present study were compared with those enrolled in Swiss Registry, SERAPHIN, ASPIRE, Pulmonary Hypertension Registry of the United Kingdom and Ireland, Korean Pulmonary Arterial Hypertension Registry and the French registry, with only Idiopathic cases being included in this study. This study attempts to characterize the epidemiological parameters in the Indian cohort with respect to IPAH.