Latinas compose almost 10% of the U.S. population and suffer the highest incidence of and one of the highest mortality rates from cervical cancer. Human papillomavirus (HPV) vaccination can prevent most HPV infections that cause more than 90% of cervical cancer. Unfortunately, limited knowledge and low rates of HPV vaccination persist among Latinas. The current study compared awareness, knowledge, beliefs, acceptability, uptake, and 3-dose series completion of HPV vaccination between Latinas who prefer English (EPL) and those who prefer Spanish (SPL), ages 18-62, living in Southern California. (The 3-dose series completion was based on HPV vaccine completion guidelines at the time of the study. HPV vaccination guidelines do change over time to improve coverage.) More EPL (n = 57) than SPL (n = 150) reported significantly (a) more HPV vaccine awareness and more knowledge of where to access the vaccine and additional vaccine information and (b) greater endorsement of vaccine effectiveness and safety (p < .05). Regardless of language preference, Latinas reporting knowledge of where to access the vaccine and additional information endorsed greater acceptability of the vaccine and more favorable beliefs regarding vaccine safety and effectiveness (p < .05). In multivariate analyses, language and income predicted the outcomes of knowledge regarding accessing the vaccine and additional information. Only 15.6% of all eligible Latinas (n = 45) initiated the HPV vaccine, with 8.9% completion. Interventions seeking to improve HPV vaccination should address linguistic and socioecological differences within Latinas to enhance effectiveness.