The demand function for vaccines against typhoid fever was estimated using stated preference data collected from a random sample of 1065 households in Hue, Vietnam, in 2002. These are the first estimates of private willingness-to-pay (WTP) and demand functions for typhoid vaccines in a developing country. Mean respondent WTP for a single typhoid fever vaccine ranged from US$2.30 to US$4.80. Mean household WTP estimates (vaccinating all members of the household) ranged from US$21 to US$27. Demand was similar for vaccines with different degrees of effectiveness and intervals of duration. These results suggest a significant potential for private sector provision of typhoid fever vaccines in Hue.