Few Texas Latino girls initiate and complete the human papillomavirus (HPV) vaccine series, but few studies have examined predictors of initiation and completion in this group. Mothers are crucial to vaccine uptake. Using self-reported data from mothers of unvaccinated girls (n = 317), we examined the association between predictors (HPV and HPV vaccine knowledge, vaccine self-efficacy) and outcomes (initiation and completion). Despite an increase in HPV and HPV vaccine knowledge from baseline to follow-up (n = 195), we found no association between the predictors and the outcomes. Findings showed that health insurance status and study group participation (Entre Madre e Hija program or brochure only) were associated with initiation and completion.