This case report of an acute exertional compartment syndrome involving predominantly the superficial posterior compartment emphasizes several important facts: (1) The subacute recurring syndromes, if left untreated, may develop into an acute syndrome. (2) The diagnostic findings separating the acute syndrome from the chronic forms are marked pain with passive stretch of the involved muscles, paresis, and sensory deficit.8,12,15, (3) In the acute form, immediate fasciotomy is mandatory and often results in full recovery. (4) All four major compartments of the leg are susceptible to chronic or acute compartment syndromes initiated by exertion. These compartments can be decompressed as necessary through a limited skin incision as recently reported.11 (5) The need for an easily obtainable and reproducible method for measuring intracompartment pressures (e.g., the wick catheter technique) is indicated.