Bamboo fibre is becoming more important as reinforcement in polymer composites owing to its environment sustainability and cost effectiveness. This study examines the performance of bamboo/polyester concretes under impact loading. Specimens at fibre volume fractions of 40 vol.%, 50 vol.% and 60 vol.% and 3 mm, 7 mm and 10 mm fibre lengths were fabricated. Results showed that the optimum impact resistance was attained at 50 vol.%/10 mm, with 16.6 times higher compared to neat polyester. Scanning electron micrographs revealed that the failure mechanisms include matrix cracking, fibre/matrix debonding, fibre pull-out, fibre end damage, fibre splitting and sand particles debonding. In addition, by relating the experimental results to a theoretical model, the damage zone size was found to increase with the fibre length except at 60 vol.%/10 mm, which could be due to fibre–fibre interaction. Results suggest that bamboo fibre is a good candidate to enhance the impact resistance of polyester concrete.