Monkeypox is an emerging zoonotic disease and a potential biological weapon. It is caused by enveloped, complex, double-stranded DNA Orthopoxvirus (Poxviridae), closely related to smallpox virus. Since 1958 monkeypox has been reported in people in several central and western African countries, USA and Europe. Transmission of monkeypox virus (MPV), occurs when a person comes into close contact with skin lesions, body fluids, respiratory droplets from infected animal or human, or with contaminated fomites. Monkeypox is a communicable disease in nonhuman primates, wild rodents and prairie dogs. Clinical symptoms in prairie dogs and hon-human primates include cough, history of fever, conjunctivitis, lack of appetite, respiratory signs and rash. In humans, the disease begins with fever, headache, muscle aches, and exhaustion. The patient develops a rash progressing to macules, papules, vesicles, pustules and scabs, often resembling chickenpox. In monkeypox human cases lymphadenopathy is prominent distinguishing this disease from smallpox, already eradicated worldwide. In the African epidemics, 90% of the patients were children below 15 years of age. Monkeypox can be diagnosed with molecular methods (RT-PCR, pan-orthopox PCR), immunohistochemistry, isolation of MPV in cell culture, ELISA and or electron microscopy. To treat patients and to control monkeypox outbreak, the smallpox vaccine, antivirals drugs, and vaccinia immune globulin (VIG) can be used. Monkeypox is a disease of global public health importance and in this article major issues related to this emerging zoonosis are presented.