As part of a larger face-to-face immunization coverage survey, 1347 families of infants (18-24 months) were questioned on their willingness to pay for a reduction in the number of concomitant vaccine injections. The median willingness to pay for a reduction by 1 injection was 5 EUR. The responses fell into 3 broad categories (willing to pay nothing at all, or anything, or a finite amount) and were hardly influenced by socioeconomic determinants. These results suggest that more sophisticated methods are required, and similar analyses should exert a similar level of caution when presenting their results.