OBJECTIVE: Conduct cost effectiveness analysis of vaccinating children in the UK under one year or aged 1 to 4 years against meningococcal serotype C disease. METHODS: A model was developed to estimate the number of cases and deaths avoided and years of life gained over a lifetime. The incidence of disease was based upon menigococcal disease reported in the UK and assumes 34% is serotype C. The vaccine efficacy was assumed to be 90% based on clinical evidence. Estimated direct medical resources consumed in the acute management of meningococcal disease, acute, and short-term sequelae were obtained from physician opinion. The costs associated with the management of hearing loss, cerebral palsy, seizures, and mental retardation over the long term were obtained from published studies conducted in the UK and included direct medical and indirect costs. Resource unit costs were obtained from published sources. Vaccination program costs were included. Future costs were discounted 5%. RESULTS: The incremental cost per year of life gained in the under one year old group was 4,280 without discounting the benefit and 6,357 with discounting. The incremental cost per life year gained in the cohort aged 1 4 years was 1,060 without discounting the benefit and 1,557 with discounting the years of life gained. Both age group ratios increase as the costs of managing acute and long-term sequelae are decreased. Assuming a higher proportion of meningococcal infections are serotype C (40%) results in ratios of 3,146 and 470 for the younger and older groups, respectively. CONCLUSIONS: The cost-effectiveness ratios for vaccinating children under age 1 and between ages 1 and 4 fall within the generally acceptable range of costs for adopting new technology.