We sought to assess if electronic messaging/reminders could increase human papillomavirus (HPV) vaccine completion among adolescents and HPV knowledge among their parents. The study was conducted in two clinics in eastern North Carolina from March 2014-March 2016. Participants included English-speaking and/or Spanish-speaking, uninsured or Medicaid-insured parents and their children (ages 9-17). Intervention participants received text/email appointment reminders and education messages and controls received standard-of-care. The final sample included 257 parent-child dyads. Most identified as Black (60%) or Hispanic (28%). Completion rates for intervention and control groups were similar for HPV dose 2 (65% vs. 65%) and HPV dose 3 (35% vs. 30%), respectively. Although knowledge change was higher for the intervention group, this difference was not statistically significant. Those who reported provider vaccine recommendation were 1.8 times more likely to complete the series. Electronic reminders to promote vaccine completion were not effective in this population. More research is needed.