Idiopathic pulmonary fibrosis (IPF) is a devastating progressive disease of unknown etiology that carries a grim prognosis. Over the last few decades there have been significant advances in our understanding of the mechanisms that drive the fibrotic process. In this review, we discuss the natural history of IPF, recent discoveries of the genetic factors, and environmental and infectious exposures that influence the development and progression of the disease, and highlight some of the novel discoveries in our understanding of the mechanisms that govern lung fibrosis. Finally, we discuss the new and exciting therapies that are now available to manage this illness.