Mycobacterium celatum is nontuberculous mycobacterium which is rarely pathogenic in human. We describe the case of M. celatum infection in immunocompetent patient. Caucasian 64-years old female patient was referred to the outpatient service because of pulmonary hemorrhage, cough and fever up to 39oC. She reported previous pulmonary tuberculosis (TB) 3 years ago. At presentation the physical examination was unremarkable.  Chest computed tomographic scan showed multifocal bronchiectases and upper lobes consolidations suggestive. Empiric antibiotic therapy with amoxicillin was undertaken. At the same time the consecutive sputum samples were immediately analyzed. Smears of six from eight sputum specimens were positive for acid-fast bacilli by Ziehl-Neelsen staining. Culture from each specimen produced slow-growing mycobacterium, identified as M. celatum by mycolic acid analysis with high performance liquid chromatography. The treatment with clarithromycin and ciprofloxacin was continued for 18 months with clinical improvement. Conclusion- we present the accuracy of microbiological diagnosis of M. celatum in patient with normal immune status, which allowed successful treatment. M. celatum infection was reported in HIV infected patients or with the history of pulmonary TB prior to mycobacterial infection. Also in our patient the TB in anamnesis may indicate “hidden immunodeficiency”.