Objective: Diffuse parenchymal lung diseases (DPLD) includes a group diseases characterised with lung parenchymal damage and have various diagnostic and treatment modalities. By this study, we aimed to present characteristics of our DPAH patients and our diagnostic and therapeutic approaches. Material and Methods: Among patients that have applied to our outpatient clinic between January 2005- December 2010, 145 patients with DPLD diagnosis were evaluated retrospectively. The data regarding their clinical, radiological and laboratory findings were obtained both from their manually filled records and electronic hospital records. Patients were categorized and evaluated according to their final diagnosis. Results: Out of 145 patients 53.7% of them was female and 46.2% of them was male. Mean age of the study population was 55.2±13.5 years (range: 21-83). Dyspnea with 78.6% was the most common symptom at admission and fine crackles (68.9%) and clubbing (22.7%) were the most common physical examination findings. Idiopathic interstitial pneumonia (42%), sarcoidosis (24.1%), lung involvement of connective tissue disease (ILD-CTD) (19.3%) were constituted the most common diagnoses. In the aspect of the mostly used diagnostic procedures, 60% of the patients were diagnosed by using clinical and radiological findings and 40% of the patients were underwent an invassive prochedure. Mediastinal or scalene lymph node biopsy (16.5%), surgical lung biopsy (11%) and bronchoscopic prochedures (8.2%) were the commonly used invassive methods. By considering the treatment results, good clinical and radiological response was found in patients with sarcoidosis (37%) and ILD-CTD (30.6%). Conclusion: In our study, sarcoidosis and idiopathic pulmonary fibrosis were the most commonly seen diseases. Although DPLD is a difficult challenge to diagnose in clinical practice, novel diagnostic approaches are fundamental for appropriate diferantial diagnosis and treatment success.