Objective. To evaluate the effects of an 8-week water physical therapy program on cervical and shoulder pain, pressure sensitivity, and the presence of trigger points (TrPs) in breast cancer survivors. Design. Randomized, controlled trial. Setting. To date, no study has investigated effects of water therapy in breast cancer. Patients. Sixty-six breast cancer survivors were randomly assigned into two groups: WATER group, who received a water exercise program or CONTROL group who received the usual care treatment for breast cancer. Interventions. The WATER therapy program consisted of 24 sessions (3 times/week over 8 weeks) of low-intensity exercises in a warm pool (32 degrees C). Each session included 10-minute warm-up period; 35 minutes of aerobic, low-intensity endurance, and core stability training; and a 15-minute cool-down period (stretching and relaxation). Outcomes. Neck and shoulder pain (visual analog scale, 0100 mm), pressure pain thresholds (PPTs) over C5-C6 zygapophyseal joints, deltoid muscles, second metacarpal, and tibialis anterior muscles, and the presence of TrPs in cervical-shoulder muscles were assessed at baseline and after the 8-week program by an assessor blinded to treatment allocation. Results. The WATER group demonstrated a between-group improvement for neck pain of -31 mm (95% confidence interval [CI]-49 to -22, P < 0.001; effect size 1.1, 0.811.75) and for shoulder-axillary of -19 mm (-40 to -04, P = 0.046; effect size 0.70, 0.141.40). Improvements were also noted for PPT levels over C5-C6 joints (between-group differences, affected side: 27.7 kPa, 95% CI 3.950.4; unaffected: 18.1 kPa, 95% CI 6.152.2). No between-group differences for PPT over the remaining points were observed (P > 0.05). Finally, patients in the WATER program showed a greater reduction of active TrPs as compared with the CONTROL group (P < 0.05). Conclusions. An 8-week water therapy program was effective for improving neck and shoulder/axillary pain, and reducing the presence of TrPs in breast cancer survivors as compared with usual care; however, no significant changes in widespread pressure pain hyperalgesia were found.