Lymphedema is an adverse effect of breast cancer surgery. Aqua lymphatic therapy (ALT) is a novel treatment for limb volume reduction. Objective The aim of this study was to examine whether ALT is a safe method and whether there are differences in adherence, limb volume, and quality of life between women who perform only self-management treatment and women who participate as well in ALT. Design Design of the study was single-blind randomized clinical trial. Setting The setting was in a hydrotherapy pool, 1.2 m depth, and a temperature of 32–33°С. Patients Forty-eight women (56±10 years), with a 12.8% lymphedema relative volume, participated in the study. Intervention The control group was instructed to perform the self-management treatment. The study group joined a weekly session of ALT for 3 months in addition to the self management therapy. Measurements Adherence was assessed by a self-reported diary, limb volume by a water displacement device, quality of life by the Upper Limb Lymphedema Questionnaire (ULL27), prior to, and after the intervention period. Results There was no episode of arm infection or aggravation in limb volume during the study period. ALT had a positive, statistically and clinically significant immediate effect on limb volume but no long-term effect was noted. The adherence rate to ALT was significantly higher than the adherence to self-management therapy. QOL improved in the study group. Conclusion ALT was found to be a safe method, with high adherence, in treating women who suffer from mild to moderate lymphedema.