Abstract Background Falling and gait difficulties in people with Parkinson’s disease (PD) are associated with impaired reactive postural adjustments and impairments in attentional resources. Combined intensive balance motor and cognitive exercise can be beneficial. However, uncertainties persist regarding the true effects and safety when applying such training. Using trampoline beds may be a favorable safe environment for a highly intensive, cognitive, and balancing training approach. The primary goal of this randomized controlled trial is to assess the effects of an intensive cognitive-motor training program in a safe trampoline environment in addition to usual care on balance impairment, gait, physical capacity, fear of falling, falls frequency and severity, cognition, and clinical impairments in people with mild or moderate PD. Methods Sixty participants diagnosed with idiopathic PD, in stage 2–4 Hoehn and Yahr, with a clinical history of gait deficits and a fall history (at least one fall in the last 6 months) will be recruited and randomly allocated to an intervention group receiving cognitive-motor trampoline training or a control group undergoing their usual care. The intervention will consist of 8-week individual training sessions (1-h training, 3 days per week) led by specialized physiotherapists that will provide progressive, challenging training, and guarantee safety. Assessment will be conducted prior to and immediately after the 8-week intervention and at 3 months follow-up after participating in the study. Primary outcome measures will be balance performance (assessed using the Mini-BEST Test and nonlinear analysis) and change in gait parameters (Motor and Cognitive Timed-Up-Go and nonlinear analysis). Secondary outcomes will be change in clinical improvement (Movement Disorder Society Unified Parkinson’s Disease Rating Scale), falls (falls weekly registry), fear of falling (assessed using the Falls Efficacy Scale), physical capacity (6-min walk test), and cognition (Montreal Cognitive Assessment). Discussion This study will provide new evidence on the benefits of intensive cognitive-motor balance training on a trampoline for people living with PD. Better guidance on how professionals can apply safer dual-task balance and gait training in rehabilitation is needed. Trial registration ISRCTN Registry ISRCTN13160409. Retrospectively registered on February 23, 2022