Actuality: Differential diagnosis of pulmonary TB and nontuberculous mycobacteriosis (NTM) is complicated because of similar clinical, radiologic, histopathologic manifestation and based on detection of certain type of Mycobacterium. The aim is to compare probe-based confocal laser endomicroscopy (pCLE) images in patients with TB and NTM Material and Methods: In retrospective study included 17 patients with one side or bilateral pulmonary infiltrates (12 with TB and 5 with NTM). Diagnosis in all patients proved by microscopy, culture or PCR examination. pCLE was made by Cellvizio system with 480 nm wavelength and 1.4-mm probe Alveoflex (Mauna Kea Technologies, France) during bronchoscopy under local anesthesia. Morphometric measurements and detection of specific patterns were made by Cellvizio viewer software. Chi-square test was used for statistical analysis. Results: Differences between average diameter of alveoli (285,9±51,9 vs 283,3±54,7), alveolar fibre thickness (14,9±5,6 vs 13,8±8,7), microvessel diame