Pulmonary hypertension is defined as 25mmHg or higher mean pulmonary arterial pressure measured by right heart catheterization. Miscellaneous diseases may cause PH. Among these are pulmonary arterial hypertension (PAH), left heart disease, pulmonary disorders and hypoemia, and chronic thromboembolic disease. Pulmonary hypertension (PH) is seen frequently in the elderly. Although diseases resulting in systolic and diastolic dysfunction with accompanying pulmonary venous hypertension (PVH) account for a large percentage of PH in this population, PH associated with other respiratory diseases, such as chronic obstructive pulmonary disease (COPD), interstitial lung disease (ILD), and sleep apnea can also be seen. Idiopathic pulmonary arterial hypertension (IPAH) is, although rarely, seen and requires careful exclusion in older patients. PAH associated with connective tissue disease is the most encountered form of PAH. Since the treatment to all these disease is different, differential diagnosis has the utmost importance.