Peer counseling in schools is a widely adopted strategy to address adolescent risk behaviors such as substance abuse, sexual activity, and violence. A cross-sectional survey was conducted with a sample of 500 students from four randomly selected secondary schools in Eastern Uganda. Data were collected through self-administered questionnaires and validated by trained interviewers. The findings indicate that peer counseling programmes led to a significant decrease in alcohol consumption (from 42% to 30%) among the adolescent participants. School-based peer counseling programmes are effective in reducing risk behaviors among adolescents, particularly in terms of substance abuse. However, further research is needed to explore their impact on other risk behaviors and sustainability factors. Programmes should be sustained with adequate training for counselors and resources. Community involvement is also recommended to enhance programme effectiveness.