Background: Human papillomavirus (HPV) knowledge has rarely been investigated in the context of a national vaccination program. The present study investigated HPV knowledge after the introduction of a national HPV vaccination program in Australia using a national sample of men and women. Methods: Questions assessing HPV knowledge were part of a broader national study of health and relationships administered via a computer-assisted telephone interview. These findings are from wave four of the study, conducted between 2007 and 2008. Knowledge questions about HPV included its association with cervical cancer, genital warts and abnormal Pap tests. Results: A total of 2634 women and 2556 men between the ages of 18 and 70 were interviewed. Overall, 62.8% (95% confidence interval (CI): 60.8–64.7%) of women and 38.3% (95% CI: 36.3–40.4%) of men had heard of HPV. Of these, 66.0% (95% CI: 64.1–67.9%) correctly answered that HPV is associated with cervical cancer, 50.2% (95% CI: 48.2–52.1%) answered that HPV is associated with abnormal Pap tests and 44.5% (95% CI: 42.5–46.5%) answered that HPV causes warts. Predictors of good knowledge included being female, aged between 26 and 45, holding higher education levels and older age at first sex. Ever having a Pap test was also associated with awareness about HPV. Conclusion: One of the highest levels of knowledge about HPV in Australia to date is reported in the present study. Knowledge about the association between HPV and cervical cancer was particularly high, especially when compared with knowledge of the association with genital warts. This appears to be a consequence of the marketing of the HPV vaccine as a vaccination against cervical cancer.