The stigmatization of some groups of people, whether for some characteristic they possess or some behavior they engage in, will initially strike most of us as wrong. For many years, academic work in public health, which focused mainly on the stigmatization of HIV-positive individuals, reinforced this natural reaction to stigmatization, by pointing out the negative health effects of stigmatization. But more recently, the apparent success of anti-smoking campaigns which employ stigmatization of smokers has raised questions about whether stigmatization may sometimes be justified, because of its positive effects on public health. Discussion of the issue so far has focused on consequences, and on some Kantian considerations regarding the status of the stigmatized. In this article, I argue that further Kantian considerations regarding the treatment of the general public (the potential stigmatizers) also count against any public health policy involving stigmatization. Attempts to encourage stigmatization are likely to fail to appeal to the rational decision-making abilities of the general public, and the creation of stigmatized groups (even if they are stigmatized for their voluntary behavior) is an obstacle to the self-improvement of members of the general public.