In this study, we compared the likely cost-effectiveness of alternative strategies for controlling a school-based measles outbreak. The analysis involved assessing the expected costs and number of cases in a school-based outbreak of measles, with no intervention and with each of six control strategies. The marginal cost per case prevented ranged from $32.90 when only previously unvaccinated school children were offered vaccination to $6795 when vaccination was extended to the siblings of school children aged 6 to 12 months. This study provided further evidence of the cost-effectiveness of vaccination in outbreak control, and yielded useful information to inform control strategies in the event of a school-based outbreak. Decisions about which groups of children to aim at and whether to conduct school-based clinics will be influenced by local circumstances, particularly the baseline measles vaccination rate and the measles attack rate among infants.