We examine the role of ill-health in retirement decisions in Britain, using the first eight waves of the British Household Panel Survey (1991-98). As self-reported health status is likely to be endogenous to the retirement decision, we instrument self-reported health by a constructed Ñ¨ealth stock' measure using a set of health indicator variables and personal characteristics, as suggested by Bound et al (1999). Using both linear and non-linear fixed effects estimators, we show that adverse individual health shocks are an important predictor of individual retirement behaviour. We compare the impact of our constructed health measure on economic activity with that arising from the use of other health variables in the data set. We also examine the impact of the 1995 reform of disability benefits on the retirement decision.