Aim. To evaluate information content of confocal laser endomicroscopy with targeted biopsy in verifying etiology of extrahepatic bile duct strictures.Material and methods. There were 28 patients with extrahepatic bile duct strictures who underwent retrograde intervention with confocal laser endomicroscopy and targeted biopsy. Data of confocal laser endomicroscopy and biopsy were compared with final postoperative and histological diagnosis. Follow-up within 1–4 years after endoscopic treatment was also considered.Results. Diagnostic sensitivity, specificity and overall accuracy of the method in differential diagnosis of common bile duct strictures were 91.7%, 93.7% and 92.8%, respectively. Complication (acute edematous pancreatitis) occurred in 1 (3.6%) case.Conclusion. Confocal laser endomicroscopy is new effective method for in vivo microscopic assessment of mucous membrane. Despite technical complexity, the method is not associated with advanced morbidity and, accordingly, has no additional contraindications in comparison with ERCP.