Pertussis in adolescents and adults is common, endemic, and epidemic worldwide, and its incidence is reportedly increasing. Although a number of individuals suffer only a mild cough, many others have symptoms typical of pertussis, causing prolonged cough illness, frequent use of health care resources, missed work and a variety of complications. Symptoms experienced by adolescents and adults include sleep disturbance, weight loss, pharyngeal discomfort, influenza-like symptoms, sneezing attacks, hoarseness, sinus pain, headaches and sweating attacks. Even when symptoms are typical of pertussis, the diagnosis is often not considered in adolescents and adults because of a low awareness of the disease in these age groups. Contrary to common perceptions, complications of pertussis, including some that are serious, are not infrequent in adolescents and adults. These include urinary incontinence, rib fracture, pneumothorax, inguinal hernia, aspiration, pneumonia, seizures and otitis media. Despite underreporting, hospitalization of adults and adolescents does occur. Many believe that adolescents and adults are the groups most commonly infected with pertussis and are now the major source of contagion to infants and young children. Because of the considerable health burden, there is a need for improved vaccination strategies to prevent disease in adolescents and adults and to reduce the risk of transmission to vulnerable infants.