Objective: Although at high risk of contracting the human papillomavirus (HPV), less than one-half of US college women have been vaccinated. The purpose of this study was to identify underlying factors influencing college women's intention to get the HPV vaccine via developing an instrument using the Reasoned Action Approach (RAA). Setting: Data were collected from college women at a large, public university in the Midwest USA via paper-pencil surveys. Design: The survey instrument was based on the RAA's major constructs (attitude towards the act, perceived norms, perceived behavioural control) and was administered to a sample of 279 female college students. Results: Results indicated that attitude towards the act (ß = 0.360, b = 0.694, standard error [SE] = 0.092, t = 7.53) and perceived norms (ß = 0.396, b = 0.544, SE = 0.068, t = 8.031) were the major predictors of intention to get vaccinated. Specifically, perceived consequences of getting the vaccine, such as protection against HPV and cervical cancer, were primary determinants influencing intention, and participants indicated that salient referents influenced their intention to get vaccinated. Conclusion: Using theory-based approaches to study a particular health behaviour such as HPV vaccination can aid the design of interventions as they help specify the underlying determinants influencing behaviour. Our findings suggest that such interventions should focus on attitudes and perceived norms, as these constructs were the strongest predictors of intention to get the vaccine. Our findings also add to the current body of literature supporting the relationship between the RAA constructs.