Deep posterior compartment syndrome is an extremely rare complication of ankle fracture and the few reported cases in the literature show that it is usually diagnosed late. Anterior and deep posterior compartment syndromes have been described with variable manifestations according to the compartment affected. We present a case of deep posterior compartment syndrome isolated to the disputed distal " subcompartment" of the leg, which had a very subtle and late presentation and was missed. The diagnosis of compartment syndrome was confirmed on MRI scan. Subsequently the patient developed a flexor hallucis longus muscle contracture that was managed nonoperatively.