Background Diffuse parenchymal lung diseases (DPLD) compromise heterogeneous subtypes. Establishing an accurate diagnosis is paramount. Lung tissue biopsy is the gold standard diagnostic tool. Aim To assess the role of medical thoracoscopy with electrocautery in the diagnosis of DPLD. Patients and methods A total of 20 patients who had undiagnosed DPLD on chest high-resolution computed tomography were randomly selected from Menoufia Chest Department from March 2017 to March 2019. Lung biopsy was taken by medical thoracoscopy under conscious sedation with the aid of electrocautery device. Results A total of 12 (60%) patients were males, and seven (35%) patients were smokers. The mean age was 58.1±10.5 years. High-resolution computed tomography patterns were reticulonodular (65%), ground glass (35%), miliary shadow (15%), and consolidation (15%). Diagnoses were granulomatous lung disease (40%), idiopathic interstitial pneumonias (30%), malignant lung disease (15%), and interstitial lung disease secondary to rheumatoid disease (10%). One (5%) case remained undiagnosed. The mean duration of hospital stay for the studied group was 1.95 days, ranging from 1 to 6 days. Recorded complications were air leak (5%), wound infection (5%), and surgical emphysema (5%). There were no reported mortalities. Conclusions Medical thoracoscope is a safe, effective, and feasible method to obtain lung biopsies for diagnosis of DPLD.