Context - Medication nonadherence among adolescent heart transplant recipients can have overwhelming negative consequences including rejection and mortality. Because of issues specific to adolescents such as peer pressure, risk taking, independence, self-image, and self-esteem, they are a population susceptible to nonadherence. Adherence may be associated with a supportive environment, fewer physical and cosmetic side effects, and a sufficient knowledge of therapies. Adherence also may be related to regimens with fewer medications, predominantly fewer immunosuppressive drugs. Objective - To examine the differences in motivation between adolescents who are more adherent and those who are less adherent to their medication regimen following transplant surgery. Design - A descriptive design and mixed methodology, including a modified written survey, the Frazier Noncompliance Inventory; a self-report measure of overall medication adherence; and an interview designed by the investigator. Interview questions were reviewed for content validity by nurse clinicians and researchers. Setting - A heart transplant follow-up clinic in the southeastern United States. Results - Findings for 2 participants revealed striking contrasts in adolescent issues and factors affecting adherence. These findings are presented in a case comparison. Data show that a supportive environment and knowledge of medications were significant in increasing self-responsibility and adherence in adolescent transplant recipients. Also, experiencing rejection early in treatment because of less adherence led to increased adherence for fear of further rejections or death.