Policy decisions regarding whether to incorporate new vaccines into routine public health practice in developing countries will depend in part on the costs of vaccine purchase and of vaccine delivery. In March, 1997, a large-scale effectiveness trial of a locally produced, orally administered bivalent vaccine against Vibrio cholerae 01 and 0139 began in Viet Nam. Empirical data obtained from the trial was used to determine the costs of the immunization campaign from the government perspective. The study population, including the children less than one year of age and pregnant women who were ineligible for immunization, was 353926. A total of 289041 persons received two doses of vaccine, and 13340 persons received one dose of vaccine. Two-dose vaccine coverage was 83.4%. The total cost of vaccine delivery during the immunization campaign was $66527. The cost of each dose of vaccine was $0.31. Therefore, the total cost of the immunization campaign was $0.44 per dose administered, and $0.91 per fully immunized person. Attempts to reduce the cost per dose of vaccine (e.g. the use of a monovalent vaccine against serogroup 01) are likely to have a large impact on the cost of future similar immunization campaigns.