OBJECTIVES: The 7-valent pneumococcal conjugate vaccine (PCV7) and 23-valent pneumococcal polysaccharide vaccine (PPV23) are currently recommended for childhood and adult vaccination respectively in the UK.  A 13-valent pneumococcal conjugate vaccine (PCV13) is currently being reviewed by regulatory authorities for use in infants and young children, and a clinical development plan for adults is ongoing. This study assessed cost-effectiveness of PCV13 compared to the current vaccination strategy and to PCV7 given to children alone. METHODS: A steady state, static cohort model was constructed comparing PCV13 vaccination of the birth cohort and of 65-year old adults with the current strategy and with PCV7 in children alone. The model con sidered the incidence and subsequent costs of four infections: pneumococcal meningitis; pneumococcal bacteraemia; all cause pneumonia and acute otitis media (AOM). Vaccination was assumed to have effects on vaccinated individuals and to impact unvaccinated individuals as a result of herd immunity. The number of cases and subsequent costs that would occur were estimated in the different scenarios.  Sensitivity analysis considered incidence, mortality rates, vaccine efficacy, serotype cover, costs, discount rate, uptake and herd immunity. RESULTS: The model estimated that, compared to the current strategy (and compared to PCV7 alone), PCV13 would reduce the annual incidence of bacteraemia and meningitis by 1176 (1303) cases, prevent 35 (40) deaths, increase life years by 619 (666), increase QALYs by 694 (731) and reduce medical costs by £2.9m (£11.1m).  Results are sensitive to vaccine effects against pneumonia and the disease incidence in non-vaccinated individuals. CONCLUSIONS: Paediatric and adult PCV13 vaccination in the UK was estimated to reduce the burden of pneumococcal disease and save costs compared with either the current vaccination strategy or a paediatric PCV7 only strategy.  Final cost-effectiveness will depend on the emergence of herd immunity benefits in the UK, impact on pneumonia, vaccine schedule and price.