Charcot foot is a rapidly progressive disease process occurring in those with peripheral neuropathy. The disease is frequently misdiagnosed resulting in a delay of appropriate treatment, worsening the outcome. We present the hallmarks for diagnosis of Charcot foot based on the clinical examination and imaging studies. We provide a simple algorithm based on evidence and experience for the investigation of the foot when Charcot arthropathy is suspected. Additionally, we propose a new classification that accounts for the degree of complications in the Charcot joint. This new system considers deformity, ulceration, and osteomyelitis, which may help to predict amputation.