Objective: The current study examined the role of family influences on the vaccine behavior of emerging adults. Participants: In Spring 2017, we conducted anonymous online surveys of undergraduate students (n = 608) at a large, public university in the mid-Atlantic. Methods: Logistic regression was used to examine associations between family factors and students' awareness of the HPV vaccine, vaccine receipt, and vaccine intentions. Family factors included sex communication, religiosity, parental monitoring, family structure, and parents' birthplace. Results: More comprehensive family sex communication is associated with less uncertainty regarding HPV vaccine receipt and greater likelihood of being already vaccinated. More frequent family religiosity and more parental monitoring are associated with greater likelihood of having decided against vaccination rather than already being vaccinated. Significant gender and racial disparities exist. Conclusion: Further research, policy, and programmatic intervention are needed to reduce disparities and to improve emerging adults' compliance with HPV vaccine recommendations.