In this study, tetanus immunity was determined in 549 randomly chosen individuals of various age groups in Ankara, Turkey. Antibody levels in sera of the individuals were measured using a double-antigen enzyme-linked immunosorbent assay. Overall, 66.5% (95%CI, 62.4-70.4) of the population studied was found to have basic protection (>= 0.01 IU/ml) against tetanus. Protective levels of tetanus antibodies declined progressively with age. The rate of protection in children and adolescents (aged < 20 years) exceeded 90%, while only 16.3% (95%CI, 8.9-26.2) of those over 60 years of age were protected. Females over 60 years of age were less immune than males of the same age group (p=0.034). Although the rates of protection in children and adolescents are regarded as satisfactory, the rates among adults are low. Preventive measures against tetanus should therefore focus on scheduled booster immunization for adults as well as children.