Although correlational studies show a relationship between worry about health concerns and higher rates of self-protective behavior, there has been no experimental research supporting the relationship and little research on the mechanisms by which worry might lead to health behaviors. This study experimentally induced a state of worry about influenza in undergraduate college students (N = 165), and examined their intentions to get a flu shot, systematic processing of a message about influenza, and vaccination behavior. The study had four main findings. First, the worry induction was successful in inducing worry about influenza. Second, participants in the experimental (worry) group reported significantly greater intentions to get a flu shot when compared with the intentions of the control group (F (1, 162) = 4.93, p < .05). A non-significant trend toward group differences in vaccination behavior was also found (27% of experimental group and 17% of control group received flu shots; β = .50, Wald = 1.28, p = .26). Third, participants in the experimental group had significantly higher rates of systematic processing of the flu message (F (1,158) = 6.89, p = .01). However, systematic processing did not mediate the relationship between worry about the flu and intention to get a flu shot. The results support the role of emotion in health behavior decisions and introduce an effective experimental technique for inducing worry about a health condition.