There is evidence of substantial benefit of cardiac rehabilitation (CR) for patients with low exercise capacity at admission. Nevertheless, some patients are not able to perform an initial exercise stress test (EST). We aimed to describe this group using data of 1094 consecutive patients after a cardiac event (71±7 years, 78% men) enrolled in nine centres for inpatient CR. We analysed sociodemographic and clinical variables (e.g. cardiovascular risk factors, comorbidities, complications at admission), amount of therapy (e.g. exercise training, nursing care) and the results of the initial and the final 6-min walking test (6MWT) with respect to the application of an EST. Fifteen per cent of patients did not undergo an EST (non-EST group). In multivariable analysis, the probability of obtaining an EST was higher for men [odds ratio (OR) 1.89, P=0.01], a 6MWT (per 10 m, OR 1.07, P<0.01) and lower for patients with diabetes mellitus (OR 0.48, P<0.01), NYHA-class III/IV (OR 0.27, P<0.01), osteoarthritis (OR 0.39, P<0.01) and a longer hospital stay (per 5 days, OR 0.87, P=0.02). The non-EST group received fewer therapy units of exercise training, but more units of nursing care and physiotherapy than the EST group. However, there were no significant differences between both groups in the increase of the 6MWT during CR (123 vs. 108 m, P=0.122). The present study confirms the feasibility of an EST at the start of CR as an indicator of disease severity. Nevertheless, patients without EST benefit from CR even if exercising less. Thus, there is a justified need for individualized, comprehensive and interdisciplinary CR.