A study was conducted on a representative sample (n=4084) of the Spanish population to assess the prevalence of antibodies to pertussis toxin (PT) and filamentous hemagglutinin (FHA). A total of 1982 men and 2102 women aged 5-59 years were stratified by sex and age (5-12, 13-19, 20-29, 30-39, 40-49 and 50-59 years). Antibodies to PT were found in 46% samples and to FHA in 74% and increased with age (p<0.0001), ranging from 35% in the 5-12 year age group to 52% in the 50-59 year age group for anti-PT and from 65 to 80% for anti-FHA, respectively. As vaccine induced-immunity wanes over time, the observed age distribution of antibodies suggests that Bordetella pertussis infection is widespread in the Spanish population and that pertussis booster vaccination in adolescents and adults with the newly developed acellular vaccines, should be considered if it is deemed necessary to control the circulation of the organism.