Balance dysfunction is a disabling symptom in people with Parkinson’s disease (PD). Evidence suggests that exercise can improve balance performance and induce neuroplastic effects. We hypothesised that a 10-week balance intervention (HiBalance) would improve balance, other motor and cognitive symptoms, and alter task-evoked brain activity in people with PD. We performed a double-blind randomised controlled trial (RCT) where 95 participants with PD were randomised to either HiBalance (n = 48) or a control group (n = 47). We found no significant group by time effect on balance performance (b = 0.4 95% CI [−1, 1.9], p = 0.57) or on our secondary outcomes, including the measures of task-evoked brain activity. The findings of this well-powered, double-blind RCT contrast previous studies of the HiBalance programme but are congruent with other double-blind RCTs of physical exercise in PD. The divergent results raise important questions on how to optimise physical exercise interventions for people with PD.