Background: Pulmonary fibrosis encompasses a group of lung-scarring disorders that occur owing to known or unknown insults and accounts for significant morbidity and mortality. Despite intense investigation spanning decades, much remains to be learned about the natural history, pathophysiology, and biologic mechanisms of disease. Purpose: To identify the most pressing research needs in the lung fibrosis community and to provide a roadmap of priorities to investigators, funding agencies, patient advocacy groups, and other interested stakeholders. Methods: An ad hoc international working group of the American Thoracic Society with experience in clinical, translational, and bench-based research in fibrotic lung diseases was convened. The group used an iterative consensus process to identify successes and challenges in pulmonary fibrosis research. Measurements and Main Results: The group identified five main priority areas in which substantial resources should be invested to advance our understanding and to develop novel therapies for patients with pulmonary fibrosis. These priorities include develop newer models of human lung fibrosis, engage current and new stakeholders to provide sustained funding for the initiatives, create a global infrastructure for storing patient-derived materials, establish collaborative preclinical and clinical research networks in fibrotic lung disease, and create a global lung fibrosis initiative that unites these multifaceted efforts into a single virtual umbrella structure. Conclusions: Despite recent advances in the treatment of some forms of lung fibrosis, many gaps in knowledge about natural history, pathophysiology, and treatment remain. Investment in the research priorities enumerated above will help address these shortcomings and enhance patient care worldwide.