This study aimed to explore willingness to use and preference for long-acting injectable PrEP (LAI-PrEP) among Thai youth at risk of HIV. A cross-sectional study was conducted in 100 Thai youth aged 18 to 24 years attending a sexual health clinic in Bangkok, Thailand. Participants received information about oral and LAI-PrEP before completing a questionnaire. Of the 98 participants willing to use pre-exposure prophylaxis, 47 preferred the injectable form. Preference for the injectable form was higher among individuals not currently using oral pre-exposure prophylaxis, affordability and longer injection intervals were key for acceptance of long-acting injectable pre-exposure prophylaxis.