Emerging coronaviruses are a global public health threat because of the potential for person-to-person transmission and high mortality rates . Middle East respiratory syndrome coronavirus (MERS-CoV) emerged in 2012, causing lethal respiratory disease in ¼35% of cases . Primate models of coronavirus disease are needed to support development of therapeutics, but few models exist that recapitulate severe disease . For initial development of a MERS-CoV primate model, 12 African green monkeys were exposed to 103 , 104, or 105 PFU target doses of aerosolized MERS-CoV . We observed a dose-dependent increase of respiratory disease signs, although all 12 monkeys survived for the 28-day duration of the study . This study describes dose-dependent effects of MERS-CoV infection of primates and uses a route of infection with potential relevance to MERS-CoV transmission . Aerosol exposure of African green monkeys might provide a platform approach for the development of primate models of novel coronavirus diseases.