Simian varicella virus was diagnosed in 2 geriatric rhesus macaques (Macaca mulatta). The macaques presented with typical skin lesions as well as severe thrombocytopenia as a result of infection. Idiopathic thrombocytopenic purpura is a known complication of varicella zoster virus infection in humans; however, this condition has not been reported previously as a complication of SVV infection. This case report discusses the clinical presentation, pathology, and thrombocytopenia of the affected macaques.