This study explored the possibility that widely held beliefs that cancer is uncontrollable underlie the public's negative attitudes toward this disease. One‐hundred‐and‐sixty undergraduates read a paragraph describing a disease that was labelled either as cancer or as “Haltmar's Disease,” a fictitious disease. The descriptions were designed to manipulate subjects' perceptions regarding both the degree to which the disease could be controlled through preventive behaviors (disease preventability) and the likelihood that it could be controlled through treatment (disease treatability). Subjects then completed a questionnaire on which they indicated their attitudes toward the described disease as well as toward a patient with that disease. Results generally supported the hypothesis that when a disease is perceived as controllable it is evaluated less negatively than when it is perceived as uncontrollable. Perceptions of control also influenced attitudes toward patients with the fictitious disease. As predicted by the Just World hypothesis, attitudes toward patients with the fictitious disease were more negative when the disease was described as uncontrollable. Attitudes toward cancer patients, however, were positive regardless of level of control. Overall, cancer was described significantly more negatively than the fictitious disease and cancer (vs. Haltmar's) patients were described significantly more positively.