BACKGROUND Pulmonary arterial hypertension (PAH) is a devastating disease characterized by elevated pulmonary pressures that lead to right heart failure and premature mortality. Patients experience multiple symptoms including dyspnea, fatigue and chest pain, but little is known about sleep disturbance, PAH symptoms, psychological distress and health-related quality of life (HRQOL) in PAH. AIM The purpose of this study was to describe the occurrence of sleep disturbance and compare PAH symptoms, psychological distress, and HRQOL across severity of sleep disturbance. METHODS One hundred and ninety-one participants completed a socio-demographic and clinical data form, PAH Symptom Severity Scale, Profile of Mood States (POMS) short form and the Medical Outcomes Short Form-36 (SF-36). Descriptive statistics were used to describe sleep disturbances; analysis of variance models were used to quantify differences in PAH symptoms, psychological distress and HRQOL by sleep disturbance groups. RESULTS The majority of participants (n=162, 85%) were women with a mean age of 53 years. Sixty-five (34%) reported no sleep disturbance; 54 (28%) mild sleep disturbance; 41 (22%) moderate sleep disturbance; and 31 (16%) severe sleep disturbance. Those reporting higher sleep disturbance severity reported worse PAH symptoms, psychological distress, and HRQOL. CONCLUSIONS Sleep disturbance is a significant finding in PAH. Increasing levels of sleep disturbance are associated with worse PAH symptoms, psychological states, and health-related quality of life. Interventions that decrease sleep disturbances may improve symptoms and HRQOL.