Purpose: This paper uses data from a 3-arm Cluster Randomized Control Trial, Suubi4Her (N = 1260; 14-17-year-old school-going girls) to (1) assess the relationship between peer pressure and adolescent risk-taking behaviors; and (2) test the mediating effect of peer pressure on an intervention on adolescent risk-taking behaviors. Methods: Students in the southwestern region of Uganda were assigned to three study arms: control (n = 16 schools, n = 408 students) receiving usual care comprising of sexual and reproductive health curriculum; and two active treatment arms: Treatment 1 (n = 16 schools, n = 471 students) received everything the control arm received plus a savings led intervention. Treatment 2 (n = 15 schools, n = 381 students) received everything the control and treatment arms received plus a family strengthening intervention. We used multilevel models to assess the relationship between peer pressure and risk-taking behaviors. We ran structural equation models for mediation analysis. Results: Using baseline data, we found that direct peer pressure was significantly associated with substance use risk behaviors, (13 = 0.044, 95% CI = 0.008, 0.079). We also found a statistically significant effect of the intervention on acquiring STIs through the mediating effect of sexual risk taking significant (13 =-0.025, 95% CI:-0.049,-0.001, p = .045) and total indirect (13 =-0.042, 95% CI:-0.081,-0.002, p = .037) effects. Also, there was a significant mediation effect of the intervention on substance use through peer pressure (13 =-0.030, 95% CI:-0.057,-0.002, p = .033). Discussion: Overall, the study points to the role of peer pressure on adolescent girls' risk-taking behaviors; and a need to address peer pressure at an early stage. (c) 2023 Society for Adolescent Health and Medicine. All rights reserved.