The 6-min walk test (6MWT) is a simple, low-cost method for estimating physical exercise capacity of cardiac patients, when exercise test cannot be performed, as in patients early after coronary artery bypass surgery. As the test requests active cooperation of patients, possibly not only somatic, but psychological factors can influence the results. 358 patients who arrived to Phase II residential cardiac rehabilitation after their first coronary artery bypass surgery were included in the prospective study. 6-MWT was performed at the beginning and at the end of 3 weeks program. Hospital Anxiety and Depression Scale (HADS), Type-D personality test were filled in 3 weeks after surgery. Patients characterized as Type-D personality (8.5%) covered considerably shorter distance than non-Type-D patients both at the beginning (255 +/- 91 m vs. 319 +/- 106 m, p < 0.01) and at the end of 6MWT (361 +/- 91 m vs. 411 +/- 106 m, p < 0.05) without any substantial differences in heart rate or rating of perceived exertion. Patients with high level of anxiety (16.5%) had lower walking distance compared to non anxious patients both at the beginning and the ending test (274 +/- 97 m vs. 320 +/- 106 m, p < 0.01 and 374 +/- 110 m vs. 413 +/- 104 m, p < 0.05), and evaluated higher rate of perceived exertion (12.5 +/- 1.1 vs. 11.9 +/- 1.4, p < 0.05 and 11.7 +/- 0.8 vs. 11.3 +/- 1.3, p < 0.05). Patients who were depressed according to HADS (14%) walked shorter distance than non depressed patients both at the beginning (267 +/- 88 m vs. 320 +/- 107 m, p < 0.01), and end of 6MWT (347 +/- 99 m vs. 416 +/- 104 m, p < 0.001). There were no differences in somatic function of patients with and without psychological alternations. Psychological factors (Type D personality, anxiety and depression) considerably influence 6MWT walking distance after coronary artery bypass surgery.