The congenital cystic dilatation of the liver and bile ducts (CDB) is a very uncommon disease. It often appears in females and most frequently in paediatric patients. Its etiopathogenesis is not yet completely defined. Its evolution includes, together with several complications, the malignant transformation. The Authors present the outcomes of their experience based on a series of 5 patients observed from 1991 till today. Apart from the rarity of this disease, their series is so interesting because 4 out of 5 are adult patients and the fifth one is over 15. In addition, differentiating from the literature trend, the group included only male patients. Are also discussed the most important aspects referring to nosology, epidemiology, etiopathogenesis, clinical pattern and its evolution of CDB, looking over a wide review too. The Authors extensively examine the diagnostic problems; owing to that the patients were observed in the period 19911999 it is necessary to clarify that some imaging methods, i.e. CSTscan and the bile duct MNR, were not yet introduced. The surgical treatment has been investigated as well, developed during its historical evolution until nowadays and our solutions for the 5 cases have been presented and discussed. In their series the Authors haven’t ever observed during hospitalisation a malignant transformation.