The study presented here was performed to determine the rates of immunity to tetanus in a cross section of the Turkish population and to assess the impact of a single-dose tetanus toxoid in previously unvaccinated individuals. Among 18-year-old participants who received their last tetanus booster 4 years prior to the study and 22-year-old participants who received the booster 8 years previously, certain durable protective antibody (>1 IU/ml) was detected in 100%. However, only 3.3% of 20-year-old participants who did not know whether they had been vaccinated as children or young adults had a protective antibody level. After administering a single dose of tetanus vaccine to this group, the rate of protective antibody increased from 3.3% to 96.7%. For the prevention of tetanus, the optimal policy should focus on improving rates of complete primary immunization in adults and children and giving a single booster every 10 years, or at least at age 40 or 50 years.