Bacillus Calmette-Guérin (BCG), a live, attenuated strain of Mycobacterium bovis, is the essential constituent of the vaccine against tuberculosis and the gold-standard adjuvant treatment for urothelial cancer of the bladder. Being a live, attenuated strain with a potential pathogenic action, bacilli can cause several complications, both locally near the inoculation site and remotely through blood dissemination. BCG-related disease can represent a side effect of anti-TB vaccination in patient with congenital or acquired immunodeficiency or a complication of the therapeutic schedule in oncologic patients. Herein we report five cases of BCG-related disease which occurred at the Infectious Diseases Department of the University Hospital of Palermo during a five-year period from January 2014 to December 2019.