BACKGROUND: Lifestyle behaviors are not well-characterized in idiopathic pulmonary fibrosis (IPF). OBJECTIVES: To assess the association between lifestyle behaviors and clinical outcomes in patients with IPF. METHODS: A total of 34 IPF patients (median age 68 years) were assessed for daily sitting and weekly walking times using the International Physical Activity Questionnaire by in-person interview at baseline, and they were followed up for up to 40 months. Cox proportional hazard analysis was conducted for cardiorespiratory-related hospitalizations and mortality as outcomes. RESULTS: Fifty percent of all patients were hospitalized, and 32% died during the follow-up period. Sitting and walking times were associated with hospitalizations and mortality in IPF. Compared to patients who reported a sitting time of <5 h/day, patients who sat 5 to <10 and ≥10 h/day experienced an increased risk of 2.4 and 5.8 (p trend = 0.036) for hospitalization and of 4.6 and 21.2 (p trend = 0.018) for mortality, respectively. Compared to patients walking <100 min/week, patients with a walking time of 100 to <150 and ≥150 min/week were associated with a 49 and 74% reduced risk for hospitalizations (p trend = 0.022) and a 62 and 86% reduced risk for mortality (p trend = 0.018), respectively. The risk for mortality was further reduced with a combination of shorter sitting and extended walking times. CONCLUSIONS: Shorter daily sitting and longer weekly walking times were associated with reduced hospitalization and mortality risks in patients with IPF. These findings suggest a clinical importance of assessing lifestyle behaviors in a comprehensive evaluation and prognostication of IPF patients. The results underscore potential clinical benefits of reducing sedentary behaviors among IPF patients; however, this warrants further investigation.