Objective To summarize the clinical characteristics of patients with diffuse parenchymal lung disease (DPLD) combined with hematological diseases in order to improve the clinicians’ knowledge of these diseases. Methods The clinical data of 46 patients was collected, who were hospitalized in Nanjing Drum Tower Hospital from January 2010 to October 2020 for DPLD combined with hematological diseases. Their clinical manifestations, laboratory tests, imaging features, diagnostic methods, treatment and prognosis were analyzed retrospectively. Results Among the 46 patients, there were 26 males and 20 females, with an average age of 60±13 years old. The main symptoms were cough and sputum, dyspnea, fever, chest tightness, and so on. Laboratory tests showed that some patients had pancytopenia or two-line cytopenia, and increase in lactate dehydrogenase, C-reactive protein, erythrocyte sedimentation rate and β2-microglobulin. Bilateral ground glass opacity, consolidations, big or small nodules, reticular shadows, and traction bronchiectasis were showed on chest high-resolution computed tomography. Among the 13 patients who were diagnosed clearly by pathology, they had 5 cases of organizing pneumonia, 4 cases of pulmonary alveolar proteinosis, 2 cases of acute fibrinous and organizing pneumonia, 1 case of diffuse alveolar hemorrhage, and 1 case of lung amyloidosis. Thirty-three patients were clinically diagnosed, including 3-case drug-induced interstitial lung disease, and 1-case exogenous allergic alveolitis. The patients with diffuse pulmonary lesions as the first manifestation and subsequently diagnosed with hematological diseases accounted for 65.2% (30/46). Among these patients, 2 of them had two kinds of hematological diseases at the same time. In the rest of the 16 cases, hematological diseases were diagnosed before DPLD. Among the 46 cases, 26 patients improved after treatment, 18 of them were treated with glucocorticoid, 8 with N-acetylcysteine and pirfenidone, 4 with granulocyte-macrophage colony stimulating factor inhaling and/ or whole lung alveolar lavage, and 2 with clarithromycin for immune regulation, etc. Fifteen patients refused treatment and transferred back to local hospital after the diagnosis of hematological diseases. Five patients died, 2 of them died of respiratory failure and 3 of them died of diseases progression. Conclusions DPLD includes many kinds of diseases, with known or unknown etiology and lack of specificity in clinical manifestations. Therefore, diagnosis for them is quite difficult. Hematological diseases themselves can be the causes of DPLD. At the same time, the treatment for hematological diseases and the related immunosuppression after treatment can also cause DPLD. In the clinical practice, careful screening and systematic differentiation are urgently needed in order to treat different causes precisely, control the conditions and improve the prognosis.