OBJECTIVE: To evaluate the usefulness of myocardial perfusion scintigraphy (MIBI-SPECT) as a diagnostic tool in well trained men. DESIGN: The study was prospective, involving 2 d stress-rest myocardial scintigraphy (MIBI-SPECT), polar map reconstruction with and without uniform attenuation correction, and comparison with a healthy male group (local Swedish) and with a commonly used reference group (American, Emory University Hospital). SETTING: University Hospital, Stockholm, Sweden. SUBJECTS: 16 healthy, male elite runners (mean (SD) age 26.1 (3.1) years). Peak oxygen uptake 73 (4) ml O2/kg/min. RESULTS: Uptake defects on polar maps were found in the majority of the runners compared with both reference groups (local Swedish 13/16, American 10/16). Most defects (91%) were fixed. Defects were located in the anterior, lateral, and posterior regions of the left ventricle. Application of a uniform attenuation correction algorithm enhanced rather than reduced perfusion defect size, probably because this correction method is imperfect in SPECT studies of the thoracic cavity. CONCLUSIONS: If myocardial perfusion scintigraphy is used for evaluating well trained men, existing normal reference files for semiquantitative evaluation appear to be inadequate.