Investigation of the health effects of retirement and age at retirement is limited, but the issue is particularly important given the pressure for an increase in the retirement age in Europe. In the Greek segment of the European Investigation into Cancer and Nutrition study, 16,827 men and women enrolled from 1994 to 1999 were either gainfully employed or had retired from such employment at enrollment; had not previously been diagnosed with stroke, cancer, coronary heart disease, or diabetes mellitus; and had complete information on important covariates and documented survival status as of July 2006. All-cause and cause-specific mortality in relation to employment status and age at retirement (among retirees) was analyzed through Cox regression models, controlling for potential confounders. In comparison to subjects still employed, retirees had a 51% increase in all-cause mortality (95% confidence interval: 16, 98). Among retirees, a 5-year increase in age at retirement was associated with a 10% decrease in mortality (95% confidence interval: 4, 15). Findings were more evident for cardiovascular than for cancer mortality, whereas, for injury mortality, there was no evidence of association. Results indicate that early retirement may be a risk factor for all-cause and cardiovascular mortality in apparently healthy persons.