Background: Many people worldwide suffer from chronic obstructive pulmonary disease (COPD). Diverse medical conditions have been treated using hydrotherapy for many years but its use in the treatment of COPD is a recent development. Its use in the COPD population may lead to improvements in cardiopulmonary outcomes and quality of life (QoL) and the mastery of activities of daily living (ADL) in people with this disease. Objectives: To determine the effects of hydrotherapy on cardiopulmonary function, QoL, and ADL in people with COPD. Method: Studies relating to adults with non-acute, non-terminal COPD were located by searching electronic databases. Included studies were critically appraised by two independent reviewers using the Lewis, Olds, and Williams tool. Results: Nine studies met the inclusion criteria (n5207 subjects). Sample sizes of individual studies varied between 10 and 43 subjects. Three studies were of above average methodological quality, two were of average, and four were of a poor quality. Thirty-five outcome measures were identified. Cardiopulmonary parameters showed positive increases when the immersed COPD subjects exhaled into water. Aspects of QoL improved with physical training in water. Group hydrotherapy improved ADL performance. Conclusions: The few included studies, which address the use of hydrotherapy in the management of COPD, had small sample sizes and were mainly of low to moderate methodological quality. Hydrotherapy may improve cardiopulmonary, QoL, and ADL outcomes in the COPD population. Investigation into the effects of combined breathing and physical exercise during hydrotherapy, in the COPD population, is needed.