A prospective design was used to study factors which predisposed individuals to receive vaccination in response to the anticipated outbreak of swine influenza in the fall and winter of 1976. Data were obtained from a telephone survey of 286 adults in Oakland County, Michigan. Predictor variables included Health Belief Model (HBM) variables as well as measures of behavioral intention, social influence, physician's advice, socioeconomic status and past experience with flu shots. In multivariate analysis, over 40 per cent of the variance in inoculation behavior was explained by the predictors used. Path analysis revealed that most of the HBM variables' influence on behavior was mediated through behavioral intention. While behavioral intention was an important predictor of inoculation behavior, other psychosocial factors played a significant role in explaining variance in the dependent variable.