Objective: To assess the effects of 8-weeks aquatic exercise training on functional capacity, balance, and perceptions of fatigue in women with multiple sclerosis (MS). Design: A randomized controlled design. Setting: Referral center of a multiple sclerosis society. Participants: Women (age:36.4 ±8.2; BMI:24.5 ±1.9) diagnosed with RR-type (relapsing-remitting) MS. After undergoing baseline testing, participants were allocated to either an intervention (aquatic training programme) or a control group. Interventions: The intervention consisted of an 8-week aquatic training programme (3 supervised training sessions per week; session duration; 45-60 min; 50-75% heart rate reserve). Main measures: Six-minute walk test (6-MWT); balance (Berg Balance Scale; BBS), and perceptions of fatigue (Modified Fatigue Impact Scale; MFIS), at baseline and after an 8 week intervention. Differences over time between the experimental and control groups were assessed by a 2x2 (group by time) repeated measures analysis of variance (ANOVA). Results: 32 women (age:36.4 ±8.2; BMI:24.5 ±1.9) completed the 8-week aquatic training intervention (experimental group, n=17; controls, n = 15). All outcome measures improved in the experimental group; 6-MWT performance (451±58 m to 503±57 m; P<0.001); BBS (pre-test mean, 53.59±1.70; post-test mean, 55.18±1.18; P<0.001), and in the MFIS (pre-test mean, 43.1±14.6, post-test mean, 32.8 ±5.9;P<0.01). A significant group-by-time interaction was evident between the experimental and controls groups for 6-MWT:P<0.001, ηp²=0.551; BBS:P<0.001, ηp²=0.423; and MFIS: P<0.001, ηp²=0.679. Conclusions: Aquatic exercise training improves functional capacity, balance, and perceptions of fatigue in women with MS.