Objectives: People often give different weights to quality-adjusted life-years (QALYs) gained by different socioeconomic groups. It is well known that QALY gains of younger patients generally get more weight than the same QALY gains accruing to older patients. This study aims to separate these age-related preferences into "pure age weighting" and age weighting caused by full health not perceived as being the same for the old as for the young.Methods: We apply a person trade-off method in a large sample representative (N = 500) of the Dutch general adult population to estimate age weighting factors. We describe health as a percentage of what is considered full health for a given age, for which we obtain a proxy in a separate task.Results: A high amount of age weighting is observed, with QALYs to 20-year-old patients receiving approximately 1.5 times as much weight as QALYs to 80-year-old patients. At the same time, we see that individuals do not perceive full health to be the same for young and older people. In fact, the age weighting disappears once we control for these differences in full health perceptions.Conclusions: Respondents had strong preferences for the young relative to the old, but these preferences were related to full health perceptions, that is, more weight being assigned to younger because full health is at a higher absolute level for them than for the old.