BACKGROUND It is advisable that the intensity of the exercises for rehabilitation of patients with coronary artery disease does not cause myocardial ischemia. OBJECTIVE Compare the capacity of myocardial tomographic scintigraphy with the electrocardiogram capacity in ischemia detection during rehabilitation session. METHODS Twenty six patients with coronary artery disease, undergoing the rehabilitation program and with previous scintigraphy, with transient hypo-uptake have been administered a new injection of MIBI-Tc-99m during a training session when they were also monitored with dynamic electrocardiography. The rest scintigraphies, after ergometric treadmill test and rehabilitation session, were assessed in a semi-quantitative way using scores from 0 to 4 to classify each one of the chosen segments (0 = normal; 1 = discrete hypo-uptake; 2 = moderate; 3 = intense; 4 = lack of uptake). RESULTS The means of the total scores found were: at rest = 12.9; after treadmill test = 19.3; after rehabilitation session = 15.1. There were statistically significant differences among them. An individual assessment showed that in 14 cases (53.8 %) hypo-uptake to some degree was identified during rehabilitation and in 12 cases (46.6%) it was not. Monitoring with the Holter system didn't show in any of the cases a ST segment depression equal or greater than 1mm. CONCLUSIONS The exercises prescribed for patients with coronary artery disease, according to recommendations found in the literature, may trigger myocardial ischemia, assessed by scintigraphy during a rehabilitation session.