Our previous studies have shown that subjective symptoms and ventilatory function are improved by spa therapy in patients with chronic obstructive pulmonary disease (COPD). In the present study, we investigated the effects of spa therapy on six-minute walk distance in patients with COPD . Subjects were 10 patients with chronic obstructive pulmonary disease (9 males and 1 female) admitted to our hospital to undergo pulmonary rehabilitation. All patients had complex spa therapy (swimming training in a hot spring pool, inhalation of iodine salt solution, and fango therapy) for 4 weeks. Ventilatory function, six-minute walk distance, oxygen saturation and Borg scale were measured. Vital capacity, forced expiratory volume in one second, sixminute walk distance and oxygen saturation increased, but not significantly. Significant decreases were observed for Borg scale. We found that spa therapy improved ventilatory dysfunction and six-minute walk distance in patients with COPD. The results demonstrated that spa therapy may lead to better disease control and exercise tolerance in patients with COPD.