OBJECTIVE: To investigate the reliability, validity and responsiveness of the 200-metre fast walk test in patients with coronary artery disease engaged in a cardiac rehabilitation programme. DESIGN: Descriptive study. SETTING: Tertiary care hospital. SUBJECTS: Thirty stable patients with coronary artery disease (51.9 +/- 8.7 years), referred to the cardiac rehabilitation department after an acute coronary syndrome. INTERVENTION: Not applicable. MAIN MEASURES: Six-minute walk test distance, time to perform the 200-m fast walk test, peak power output of the graded maximal exercise test, before and after the programme; SF-36 quality of life questionnaire at baseline. Walk tests were performed twice at baseline to assess reliability. RESULTS: The 200-m fast walk test was highly reliable (ICC = 0.97). It was significantly correlated with the graded maximal exercise test peak power and the 6-minute walk test at baseline (r = -0.417; P < 0.05; and r = -0.566; P < 0.01, respectively) and after the training programme (r = -0.460, P < 0.05; and r = -0.926; P < 0.01, respectively). At baseline, there was a strong correlation between the 200-m fast walk test time and the physical component score of the SF-36 (r = -0.77; P < 0.01), but not between the 200-m fast walk test time and the SF-36 mental component score. Mean 200-m fast walk test time was significantly different between the patients performing </=90 W (n = 11) or >/=100 W (n = 19) at the baseline graded maximal exercise test (121.7 +/- 13.6 vs. 115.5 +/- 10.1 seconds; P < 0.05). The responsiveness was strong with a standardized response mean at 1.11. CONCLUSION: The 200-m fast walk test is a reliable, valid and responsive high-intensity walk test in patients with coronary artery disease after an acute coronary syndrome. It can thus give additional information to that given by the 6-minute walk test and the graded maximal exercise test.