Pulmonary arterial hypertension (PAH) is a pathophysiological condition characterized by pulmonary vascular remodeling and elevated vascular resistance, which may ultimately result in cardiovascular failure and sudden cardiac death. In recent years, the occurrence of pregnancy complicated by pulmonary arterial hypertension has witnessed a notable increase, whereas the incidence of postpartum pulmonary arterial hypertension is comparatively rare. This study presents a case involving a 39-year-old female who exhibited severe pulmonary arterial hypertension, finally diagnosed as idiopathic pulmonary arterial hypertension, within 2 days postpartum. The diagnosis was made following a thorough clinical examination. This case report emphasizes the significance of promptly initiating targeted therapy as an initial step in effectively managing patients and the criticality of conducting a thorough assessment of multidisciplinary collaboration in postpartum management. Furthermore, the report has the potential to enhance awareness and education regarding the future management of similarly intricate conditions.