Pulmonary fibrosis is a devastating disease that affects millions of people worldwide. Among the most common forms of lung fibrosis are idiopathic pulmonary fibrosis (IPF) and scleroderma-related interstitial lung disease (SSc-ILD). Despite a wealth of literature regarding each of these diseases, studies that directly compare IPF and SSc-ILD are rare.This review compares the salient features of IPF and SSc-ILD. Clinical presentation and demographics will be presented, along with the newly released radiographic and pathologic criteria for IPF. Evolving concepts of pathogenesis including the role of structural cell injury, the pathogenic role of macrophages and lymphocytes, and the origin of fibroblasts are described. We conclude with new developments in the search for predictive biomarkers of disease progression, such as markers of epithelial injury, lymphocyte subsets, and circulating fibrocytes, will be presented. We conclude with a discussion of the results of recent clinical trials.It is found that despite differences in clinical presentation and response to treatment, similarities are noted in proposed pathogenesis and putative biomarkers. It is hoped that this information will lead to studies aimed at understanding the factors driving these difficult to treat and often deadly diseases.