The objective of this chapter is to introduce the compartment syndrome. Acute compartment syndrome is defined as an elevation of inter-compartment pressure to a level and for a duration that without decompression will cause tissue ischemia and necrosis. Compartment syndrome is characterized etiologically by swelling arising from diverse causes resulting in compromise of the blood supply of tissues within a confined osteofascial space. Risk factors for development of or late diagnosis of acute compartment syndrome, clinical features, and diagnosis are cover in this chapter. Anterior compartment syndrome of leg, peroneal compartment syndrome, superficial posterior compartment syndrome, deep posterior compartment, delayed fasciotomy, and chronic compartment syndrome are also discussed in brief along with their clinical presentation, clinical features, diagnosis, and treatment.