Objective: To investigate the factors affecting human papillomavirus (HPV) vaccination behaviors among gynecological outpatients based on extended unified theory of acceptance and use of technology (UTAUT2), so as to provide insights into the development of HPV vaccination behavioral interventions. Methods: Patients at ages of 45 years and younger that were admitted to the outpatient department of gynecological of Shanxi Provincial People's Hospital from October 2021 to August 2022 were recruited, and the factors affecting HPV vaccination behaviors were identified using UTAUT2. Results: A total of 431 female outpatients were enrolled, including 163 patients at ages of 36 to 45 years (37.82%), 272 cases with an educational level of college degree and above (63.11%) and 253 patients with per capita monthly household income of more than 3 000 Yuan (58.70%). The coverage of HPV vaccination was 24.36%, and the main cause of non-vaccination was difficulty in high-valent HPV vaccine appointment. Price value, social impact and efficacy expectation posed a positive impact on HPV vaccination behaviors via intention of vaccination (β=0.11, 0.08, 0.07, all P<0.05) and intention of vaccination and effort expectancy (β=0.10, 0.07, 0.06, all P<0.05), and effort expectancy played a mediating effect between intention of vaccination and vaccination behaviors (β=0.28, P<0.05). Conclusion Efficacy expectation, social impact, price value, intention of vaccination and effort expectancy may positively affect HPV vaccination behaviors.