This article addresses the issue of stigmatization and discrimination towards people with AIDS (PWAs) using Weiner's attributional theory of motivation and emotion. In a field experiment, subjects responded to vignettes describing patients with AIDS, syphilis, lung cancer or tuberculosis. In these vignettes, the onset of the diseases was either described as personally controllable or as uncontrollable. Results show that although attributional variables do account for a significant amount of variance in helping behavior and emotions towards PWAs, other variables such as the incurability of the disease, the risk of infection and associations with (homo)sexuality, may be more useful in explaining reactions to PWAs. Implications for education tailored at the prevention of the stigmatization of PWAs are discussed.