It is often argued that the increased labor market participation of seniors threatens family support provided to dependent elderly people. The purpose of this paper is to assess the causal effect of retirement on the frequency of care provided by individuals aged 55-69 years to their elderly parent. Using data from the Survey of Health, Aging and Retirement in Europe (SHARE), we estimate an endogenous switching model that allows the retirement effect to be heterogeneous with respect to observed and unobserved characteristics. To tackle the possible endogeneity of selection into retirement, we use the heterogeneity of retirement rules between and within European countries. On average, being retired does not significantly impact the probability of providing care but significantly increases the frequency of care conditional on being caregiver. The same pattern is observed regardless of the individual observed characteristics, even if the provision of informal care appears to be less sensitive to the retirement status when the child cannot rely on the other parent to provide care or when both parents are in poor health. These results suggest that pension system reforms should not affect the number of caregivers. Some adverse effects on the intensity of involvement among caregivers are nevertheless expected.