We present a case of benign exertional headache (BEH) in a 15-yr-old boy. The patient suffered from exclusively exercise-induced headaches with migraine-like accompanying symptoms. No pathology could be detected by routine cardiovascular or neurological examinations by CT. The postexercise 99mTc-HMPAO brain SPECT performed during the provoked headache attack showed asymmetric bifrontal hypoperfusion. A second 99m-c-HMPAO study during a symptom-free phase under resting conditions was normal. The detection of impaired regional cerebral blood flow (rCBF) by 99mTc-HMPAO brain SPECT indicates a perfusion-related pathology in this type of headache. Analysis of rCBF with 99mTc-HMPAO in larger studies could be helpful in the clarification of BEH pathogenesis.