The causative agents of leprosy are Mycobacterium leprae and M. lepromatosis. Mycobacterium lepromatosis was found in 2008 to cause diffuse lepromatous leprosy in Mexican patients. This study aimed to identify M. leprae and M. lepromatosis in paraffin-embedded skin samples from Caribbean patients with leprosy. A total of six skin samples were obtained from the Dominican Republic. All cases presented the multibacillary form; five were nodular lepromatous leprosy, and one was borderline lepromatous leprosy. All patients received multidrug therapy. Molecular identification was achieved using the M. leprae-specific repetitive element for M. leprae and the hemN gene for M. lepromatosis. Mycobacterium leprae was identified in two lepromatous leprosy cases, and one borderline lepromatous leprosy case; M. lepromatosis was found in one nodular lepromatous leprosy case. Both Mycobacterium species were present in two nodular lepromatous leprosy cases. This is the first report of M. lepromatosis in the Dominican Republic.