Pulmonary arterial hypertension (PAH) is a rare complication of hereditary hemorrhagic telangiectasia (HHT). The triggers that promote the development of PAH in HHT remain poorly understood. We present the case of a 45-year-old woman with decompensated right-sided heart failure secondary to newly diagnosed PAH. The clinical diagnosis of HHT was confirmed on the basis of recurrent spontaneous epistaxis, multiple typical mucocutaneous telangiectasia, and the presence of pulmonary arteriovenous malformation. There was also a suggestive family history. The patient was discovered to have active and extensive stimulant abuse in addition to HHT. We concluded that there may be a temporal relationship between exposure to stimulants and development of PAH in a host with underlying gene mutation. This case highlights the paradigm of PAH development after environmental exposure in a genetically susceptible host.