Background: Falls and fall-related injuries are a major cause of morbidity and mortality among older people. Extensive research into falls prevention has established physical exercise as an efficient method to reduce falls, but the effect of exercise on serious injuries caused by falls remains unclear. Moreover, populations that would benefit most from these interventions, as well as factors that determine adherence to exercise remain underreported. Methods: ‘Ossébo’ is an on-going multicentre randomized controlled trial, aiming to assess the effect of a 2-year community-based group physical exercise program on the prevention of falls among women aged 75 to 85 years old. The primary outcomes examined are the rate of falls and injurious falls; secondary outcomes include functional capacities, fear of falling and quality of life. Discussion: This study will help determine the effectiveness of a large scale falls prevention program and the factors that can potentially assist its success.