Although frailty can arise in middle age, very few studies have investigated frailty before 65 years. Our objectives were to assess the prevalence of frailty parameters in middle-aged individuals and probe the association with future adverse events. We performed cross-sectional and longitudinal analyses of community-dwelling individuals aged 50 to 65 (n = 411, median age: 59.0) having undergone a multidomain geriatric assessment (2010-2015) in an outpatient clinic in the greater Paris area of France (SUCCEED cohort). The primary outcome was a composite measure of adverse events (non-accidental falls, fractures, unplanned hospitalizations, death), recorded in 2016/2017. Multivariable logistic regression models were built to identify independent predictors. Six frailty parameters were highly prevalent (> 20%): low activity (40.1%), exhaustion (31.3%), living alone (28.5%), balance impairment (26.8%), weakness (26.7%), and executive dysfunction (23.2%). Female sex (odds ratio: 2.67 [95% confidence interval: 1.17-6.11]), living alone (2.39 [1.32-4.33]), balance impairment (2.09 [1.16-3.78]), executive dysfunction (2.61, [1.18-5.77]), and exhaustion (2.98 [1.65-5.39]) were independent predictors of adverse events. Many frailty parameters are already altered in middle-aged individuals and are predictive of adverse health events. Our findings highlight a possible need for frailty screening and preventive programs targeting middle-aged individuals.