OBJECTIVE: To measure whether public values for health vary with the age of the affected individual. METHODS: We fielded a discrete choice experiment via the internet in December 2007 to measure preferences for different attributes of influenza-related health states: length of episode (days of illness), severity of illness (workdays lost), age of hypothetical affected individual (range: 1-85 yrs), and time-tradeoff amounts (1day – 2yrs). We also collected data on sociodemographic characteristics and experience with influenza illness. Respondents were 18 years and older and matched to reflect characteristics of the general US adult population (n=1012). Response rate was 67%. Respondents were presented with pairs of illness profiles for a hypothetical individual and indicated the profile they preferred. Each respondent answered 8 discrete choice questions. A full factorial design was used. Discrete choice analysis using generalized estimating equations was used to evaluate the relative value of different attributes in the illness profile while controlling for sociodemographic characteristics and influenza experience. RESULTS: As measured by time-tradeoff amounts, respondents preferred shorter influenza episodes (total length) but did not significantly prefer fewer workdays lost if episode length was held constant. Respondents preferred to avert uncomplicated illness in very young children (1 year old child: odds ratio=2.35, p<0.05; 3 year old child: odds ratio=3.21, p<0.01) and older adults (85 year old: odds ratio=2.41, p<0.05) compared to a 35 year old adult. For an influenza-related hospitalization, respondents preferred to avert illness in very young children (1 year old child: odds ratio=2.86, p<0.01) compared to a 35 year old adult. CONCLUSIONS: Approaches that assume values for illnesses do not vary with the age of a patient may bias economic analyses that use these values. If patient age is likely to affect valuations, then age should be included as an attribute in the valuation exercise.