Ninety-eight patients with chronic exercise-induced pain in the anterior compartment of the lower leg underwent extensive clinical and laboratory investigations to establish the diagnosis. They all were referred because of a putative chronic compartment syndrome (CCS). Intramuscular pressure was recorded bilaterally during exercise in the anterior tibial muscle in all of them. Conduction-velocity recordings of the deep and superficial peroneal nerves were performed in 29 patients. Other investigations included radiography, plethysmography, and scintigraphy. CCS was diagnosed in 26 of the 98 patients. Other diagnoses included periostitis in 41 patients, compression of the superficial peroneal nerve in 13, and miscellaneous other diagnoses in 18. CCS seems to be an uncommon reason for anterior pain in the lower legs.