This paper analyzes the reasons for differences in the estimated effect of retirement on health in previous studies. We investigate these differences by focusing on the analysis methods used by these studies. Using various health indexes, numerous researchers have examined the effects of retirement on health. However, there are no unified views on the impact of retirement on various health indexes. Consequently, we show that the choice of analysis method is one of the key factors in explaining why the estimated results of the effect of retirement on health differ. Moreover, we re‐estimate the effect of retirement on health by using a fixed analysis method controlling for individual heterogeneity and endogeneity of the retirement behavior. We analyze the effect of retirement on health parameters, such as cognitive function, self‐report of health, activities of daily living (ADL), depression, and body mass index in eight countries. We find that the effects of retirement on self‐report of health, depression, and ADL are positive in many of these countries.