Findings in this survey of grade nine students showed a number of associations between using methamphetamine and engaging in sexual risk behavior, indicating that methamphetamine use by adolescents might impact on sexual risk behavior in this population. The associations found between the use of methamphetamine and HIV risk behaviors indicate that the use of methamphetamine may escalate the risk for contracting HIV. The proportion of students who engaged in sexual risk behaviors were significantly higher for those students who had used methamphetamine recently (in the last 12 months and especially in the last 30 days) compared to those who had not used it or who had only used the drug once. Almost 60 percent of students who had used methamphetamine in the past 30 days had also had vaginal sex at least once, compared to about one in four of those who had never used methamphetamine. Students who had used methamphetamine in the past 30 days were significantly more likely to have engaged in sexual risk behaviors than those who had not used the drug and those who did not report use in the past 12 months. Findings suggest that school-based prevention and education programs particularly need to incorporate these results when finding programs focusing on Sexual Transmitted Infection (STI) prevention and those focusing on drug abuse prevention. Data were collected from 4,605 grade nine students in 15 randomly selected and 15 matched schools in Cape Town. Tables and references