Contributed equally as co-first authors; **Contributed equally as co-last authors Study Objectives: Obstructive sleep apnea (OSA) in patients with idiopathic pulmonary fibrosis (IPF) is associated with worse mortality and clinical outcome. We aimed to assess differences between patients with IPF with and without OSA and the effect of positive airway pressure treatment on sleep and overall life quality, morbidity, and mortality in these patients. Methods: Forty-five patients with newly diagnosed IPF underwent polysomnography. Using an apnea-hypopnea index ≥ 15 events/h for OSA diagnosis resulted in 16 patients with IPF and 29 with IPF-OSA. The patients completed the Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, Functional Outcomes in Sleep Questionnaire, Fatigue Severity Scale, Short Form-36 life questionnaire, and Beck Depression Inventory before and at the end of the follow-up period. Results: Patients with IPF-OSA showed the most severe functional impairments in questionnaires, especially for General Health component of the Short Form-36 life questionnaire (37 vs 58, P = .03). At the 7-year follow-up, 16 (36%) patients had died, 6 (38%) in the IPF group and 10 (35%) in IPF-OSA group. Patients with ≥6-hour positive airway pressure use had better survival compared with patients with <6-hour use (P = .04). Significant improvement was also observed in Epworth Sleepiness Scale (3 vs 6, P =.03), Pittsburgh Sleep Quality Index (5 vs 8, P =.01), and Fatigue Severity Scale (37 vs 48, P =.008) score in patients with ≥4-hour positive airway pressure use. Conclusions: OSA plays a significant role on clinical features and quality of life in patients with IPF. Effective positive airway pressure treatment results in a significant improvement in sleepiness, fatigue, sleep quality, and mortality.