This research draws upon the interpersonal-psychological theory of suicide in the development of the LEAP intervention, a web-based selective preventive suicide intervention targeting cognitions of perceived burdensomeness toward others. The pilot randomized controlled trial consisted of 80 adolescents (68.8% female, 65.8% Hispanic) 13-19 of age years who were randomly assigned to either the LEAP intervention or a psychoeducational control condition. Participants completed baseline, posttreatment, and 6-week follow-up assessments. All participants reported high levels of satisfaction with the program. Findings on outcome variables differed across intent-to-treat analyses and treatment completer analyses. Intent-to-treat analysis yielded no significant between-condition differences in perceived burdensomeness at posttreatment or follow-up. Treatment completer analyses revealed significant between-condition differences on outcome variables such that participants who completed the LEAP intervention showed significantly lower perceived burdensomeness scores at postintervention and significantly lower perceived burdensomeness, thwarted belongingness, and depressive symptom scores at follow-up as compared to participants in the control condition. No significant differences in suicidal ideation were found between conditions. These findings support the promise of the LEAP intervention as a brief, web-based selective preventive intervention for reducing perceived burdensomeness among adolescents who complete the intervention. This study provides evidence that perceived burdensomeness can be modified via a psychosocial intervention. Future research is needed to identify ways to enhance adolescent engagement with and completion of the intervention.