Facial recognition technology has been advancing rapidly, and been usefully implemented on smartphones for unlocking the devices, airport customs for security clearance, and Facebook for social networking purposes. Public libraries are adopting this emerging technology for library patron authentication mainly for the purposes of collection checkouts, access authentication, and surveillance. New Taipei City Library launched its facial recognition system in August, 2018, to assist patrons check out library materials without a library card. This study adopts the Unified Theory of Acceptance and Use of Technology model to investigate the factors that will affect user adoption of facial recognition to check out library materials. This study utilizes a structured survey method, comprised a set of questions concerning performance expectancy, effort expectancy, and social influence, and how they relate to gender, age, and user preference. The findings suggest that even though most of the participants didn’t use the facial recognition service, they are willing to try it in the future because it’s convenient and in situation of card lost or stolen, request for library materials can still be made. For the reasons of not willing to use facial recognition service, the participants report their hesitation to register yet another library service, the awkward feeling of looking at the camera, and the worry of personal information leak. Finally, the study concludes that an enabling library environment and user experience may support library users’ new technology adoption, and may also lead to new innovation and opportunities for library services.