Data were collected from the initial graded exercise tests of 116 cardiac rehabilitation patients. Subjects were grouped according to their blood pressure response to exercise. Blood pressure groupings were typical systolic and typical diastolic (S_TD_T); typical systolic and atypical diastolic ( S_TD_AT); atypical systolic and typical diastolic (S_ATD_T); and both atypical systolic and diastolic blood pressure responses to exercise (S_ATD_AT). Groups were investigated for incidence of atypical responses (decrease, no increase, or excessive increase in systolic pressure and/or excessive increase or high diastolic pressure) and differences in physical characteristics, CVD status, predisposing CHD variables, medications prescribed, peak exercise cardiovascular responses and indicators of myocardial dysfunction. Results revealed atypical blood pressure responses in 65.5% of the subjects. No change in systolic pressure between the last two measured blood pressures was the most frequent atypical response exhibited. The S_ATD_AT pattern group was suggested to be at a higher health risk than the other groups based upon the tendency for higher percentages of subjects in this group exhibiting a history of myocardial infarction (80%), CABG (20%), angina ( 40%) and hypertension (47%). A high percentage of these subjects had been prescribed antihypertensive and antiarrhythmic medications, had "borderline" resting hypertension (X = 135.2/86.3 mmHg) and smoked (61.5%). Peak exercise data revealed a higher heart rate, higher systolic and diastolic pressures, higher RPE, more marked decreases in ECG changes and more supraventricular and ventricular arrhythmias than the other groups. These results based upon observed trends suggest that cardiac rehabilitation subjects with a combination of an atypical systolic and diastolic blood pressure response to exercise may require increased medical supervision during testing, more frequent measurements of blood pressure during testing and consideration of test termination. / M.S.