This study assessed mothers' intentions to vaccinate their daughters against human papillomavirus (HPV) using the theory of planned behavior (TPB). Experience with sexually transmitted infections (STIs), beliefs about the vaccine encouraging sexual activity, and perception of daughters' risk for HPV were also examined for a relationship with intention. A random sample of mothers in a rural, Midwestern state were mailed a survey with questions pertaining to the intention to vaccinate. Attitudes were the strongest predictor of mothers' intentions to vaccinate, but intentions were not high. Subjective norms also influence intention. Mothers' risk perceptions, experience with STIs, and beliefs about the vaccine encouraging sexual activity were not related to intention. Mothers' perceptions of the daughters' risks for HPV were surprisingly low. This research provides a foundation for designing interventions to increase HPV vaccination rates. Further research should explore ways to influence mothers' attitudes and to uncover the referent groups mothers refer to for vaccination behavior. (Contains 2 tables.)