To assess cardiorespiratory fitness (CF), usually a stress test is necessary. Our aims were to assess CF in a patient population with suspected or known coronary artery disease (CAD) based on a questionnaire (quest); to compare estimated CF with achieved workloads, and to evaluate its prediction of stress modality (physical/pharmacologic). Consecutive 612 patients undergoing myocardial perfusion SPECT (MPS) completed quest. They first chose one category which best described their daily physical activities. The second part contained patient characteristics (gender, age, BMI, and resting heart rate). An activity score was calculated and metabolic equivalents (METs) were estimated. Estimated and achieved results were compared. Patients with pharmacologic test (n = 208) provided a lower estimate of their performance than physically stressed patients (n = 404): 7.0 ± 2.1 and 8.2 ± 2.3 METs, respectively (P < 0.0001). The latter showed a good correlation between estimated and achieved METs (r = 0.63, P < 0.0001). Regarding prediction of the stress modality, area under the curve (ROC) was 0.65 (P < 0.0001). The quest can easily be applied in daily practice to assess CF in a patient population with CAD and for estimating whether an adequate physical stress test can be carried out.