The enrollment of adolescents with cancer in clinical trials is much lower than younger pediatric patients. For adolescents with “adult-type” cancers, lack of access to relevant trials is cited as one of the reasons for this discrepancy. Adolescents are generally not eligible for enrollment on adult oncology trials, and initial pediatric trials for many drugs are conducted years later, often after the drug is approved. As a result, accrual of adolescents to these trials may be slow due to off-label use, prospectively collected safety and efficacy data is lacking at the time of initial approval, and, most importantly, these adolescents have delayed access to effective therapies. In order to facilitate earlier access to investigational and approved drugs for adolescent patients with cancer, and because drug exposure is most often similar in adolescents and adults, we recommend the inclusion of adolescents (ages 12-17) on disease and target-appropriate adult oncology trials. This approach requires careful monitoring for any differential safety signals, appropriate pharmacokinetic evaluations, and ensuring that ethical requirements are met. Inclusion of adolescents on adult oncology trials will require the cooperation of investigators, cooperative groups, industry, IRBs, and regulatory agencies to overcome real and perceived barriers.