Background: Policymakers in several European countries, concerned about the sustainability of their pension system, have raised the statutory retirement age. While several studies investigated the effect of retirement on health, the relationship between retirement and frailty is neglected. Notwithstanding, frailty is associated with adverse outcomes. Objective: The aim of this study was to examine the relationship between age of retirement and frailty in later life. Methods: Data of the Belgian Ageing Studies, a cross-sectional research project was used. The present study includes N=12659 participants (>60y) in 83 Flemish municipalities. To address reverse causality, only participants not retired because of health-related reasons were included. The Comprehensive Frailty Assessment Instrument, a multidimensional frailty scale with four domains (physical, psychological, social and environmental) was used to operationalize frailty. Univariate general linear regression analyses (GLM) were performed for scores on the total frailty scale and the four subdomains separately. The analysis was done for men and women separately, since both groups have different labor trajectories. Results: The present study found a negative association between age of retirement and physical frailty for both men and women in later life, and total frailty for men, although the differences were small. No evidence was found for a relation between age of retirement and the other subdomains of frailty. Conclusions: The results suggest that age of retirement is not a clinically relevant predictor for frailty in later life. Differences within and between subpopulations (e.g., profession) can shed a new light on this relation.