BACKGROUND: Falls occur annually in 25% of adults aged ≥65 years. Fall-related injuries are increasing, highlighting the need to identify modifiable risk factors. METHODS: Role of fatigability on prospective, recurrent, and injurious fall risk was examined in 1 740 men aged 77-101 years in the Osteoporotic Fractures in Men Study. The 10-item Pittsburgh Fatigability Scale measured perceived physical and mental fatigability (0-50/subscale) at Year 14 (2014-16); established cut-points identified men with more severe perceived physical (≥15, 55.7%), more severe mental (≥13, 23.7%) fatigability, or having both (22.8%). Prospective, recurrent (≥2), and injurious falls were captured by triannual questionnaires ≥1 year after fatigability assessment; risk of any fall was estimated with Poisson generalized estimating equations, and likelihood of recurrent/injurious falls with logistic regression. Models adjusted for age, health conditions, and other confounders. RESULTS: Men with more severe physical fatigability had a 20% (p = .03) increased fall risk compared with men with less physical fatigability, with increased odds of recurrent and injurious falls, 37% (p = .04) and 35% (p = .035), respectively. Men with both more severe physical and mental fatigability had a 24% increased risk of a prospective fall (p = .026), and 44% (p = .045) increased odds of recurrent falling compared with men with less severe physical and mental fatigability. Mental fatigability alone was not associated with fall risk. Additional adjustment for previous fall history attenuated associations. CONCLUSIONS: More severe fatigability may be an early indicator to identify men at high risk for falls. Our findings warrant replication in women, as they have higher rates of fatigability and prospective falls.