Human papillomavirus (HPV) vaccine 3-dose completion rates among adolescent females in the US are low. Missed opportunities impede HPV vaccination coverage.A population-based secondary data analysis of de-identified vaccination and demographic data from the Utah Statewide Immunization Information System (USIIS) was conducted. Records were included from 25,866 females ages 11-26 years at any time during 2008-2012 who received at least one of the following adolescent vaccinations documented in the USIIS: Tdap (Tetanus, Diphtheria, Pertussis), meningococcal, and/or influenza. A missed opportunity for HPV vaccination was defined as a clinical encounter where the patient received at least one adolescent vaccination, but not a HPV vaccine.Of 47,665 eligible visits, there were 20,911 missed opportunities (43.87%). Age group, race/ethnicity, and rurality were significantly associated with missed opportunity (p<0.0001). In a multivariable mixed-effects logistic regression model that included ethnicity, location and age, as fixed effects and subject as a random effect, Hispanics were less likely to have a missed opportunity than whites OR 0.59 (95% CI: 0.52-0.66), small rural more likely to have a missed opportunity than urban youth OR 1.8 (95% CI: 1.5-2.2), and preteens more likely than teens OR 2.4 (95% CI: 2.2-2.7).Missed clinical opportunities are a significant barrier to HPV vaccination among female adolescents. Interventions targeted at providers who serve patient groups with the highest missed opportunities are needed to achieve adequate protection from HPV-associated illnesses.This is one of the first studies to utilize state immunization information system data to assess missed opportunities for HPV vaccination.