Idiopathic interstitial pneumonia is a heterogeneous group of diseases. Recently, the importance of a detailed differentiation of nonspecific interstitial pneumonia from other idiopathic interstitial pneumonias has been demonstrated. Most critical appeared to be a proper classification based on clinical presentation, high-resolution CT findings, bronchoalveolar lavage fluid cell findings, and histopathology. This classification may guide the most appropriate therapeutic approach and has significant implications regarding prognosis. Recent advances in the diagnosis and management of nonspecific interstitial pneumonia, cellular and fibrosing variants, are discussed.