Introduction: Adolescent pregnancy continues to be a priority public health problem in Mexico, which requires innovative, culturally relevant interventions based on motivational theories. Digital interventions represent a promising strategy to promote preventive sexual behaviors in the school population. Objective: To evaluate the acceptability of the digital intervention “Be yourself”, based on the Self-Determination Theory, for the prevention of adolescent pregnancy. Material and methods: A pilot randomized controlled trial was carried out with a pretest-posttest design and repeated measures. A total of 150 secondary school adolescents (11-15 years) were randomly assigned to an intervention (n=75) or control (n=75) group. The intervention was implemented for three weeks through an interactive website and an educational chatbot, integrated into the school curriculum. Assessments were carried out at baseline, post-intervention and two-month follow-up. Results: The intervention showed high acceptability, with an abandonment rate of 11.3% and high retention during follow-up. Participants reported high levels of satisfaction and perceived usefulness, suggesting good adherence and feasibility of implementation in the school context. Conclusions: “Be yourself” is a viable and acceptable digital intervention for Mexican adolescents. The findings support its potential to be evaluated in efficacy trials with larger samples, contributing to the development of innovative digital strategies for adolescent sexual health.