Leprosy is a granulomatous disease affecting the skin and peripheral nerves caused by Mycobacterium leprae. The range of clinical forms varying from tuberculoid to lepromatous leprosy results from variations in the cellular immune response to the mycobacterium. Despite available combined drug-therapy, it continues to be a significant public health problem, carrying a strong stigma. Although recently there has been no native cases in Chile, a few imported cases have been diagnosed. We present a 56-year-old man who had lived in Paraguay for 8 years, and presented with leprosy 6 years after returning to Chile. The biology of leprosy, clinical features of the disease, current diagnostic criteria and approaches to treatment are discussed.