Aim of the study: This was prospective observational study with the aim of studying patients having interstitial pneumonia with autoimmune system features (IPAF) and characterizing its prognosis in contrast with idiopathic interstitial pneumonias. Follow up those IPAF patients for diagnosing who will advance to a definitive CTD. Material and methods:  This study included 55 patients who were diagnosed as diffuse parenchymal lung diseases by HRCT chest. All patients were subjected to clinical examination, HRCT, echocardiography, spirometry and collagen markers. Results: From 55 patients, 31 met the IPAF criteria, most of them were females, nonsmokers with mean age 47.56 ±10.9 years. The most common clinical finding was inflammatory arthritis. The most common serological finding was RF. The most common radiological pattern was NSIP. In outcome analysis, 2 of IPAF patients died during the follow-up period and 3 of 31 IPAF patients evolved to a definitive CTD. Conclusion: This study demonstrates that the recently defined criteria for IPAF are fulfilled by a significant proportion of patients. In this study we tried to shine a light on the basic characteristics of these patients and the nature of their disease with analysis of their clinical, morphological and serological criteria and prognosis of their disease.