Non-adherence to medications is a leading cause of organ loss and morbidity in children and adolescents who had a liver transplant. Yet there are very few published studies about ways to detect whether patients are taking their medications or not, and about treatment options to improve adherence. The Pediatric Liver/Liver Transplant Program at Mount Sinai developed clinical and research programs that evaluate adherence. We review initial results from these programs. Clinic patients participate in an adherence-monitoring program that involves standardized assessments by patients, parents, clinicians, and routine examinations of medication blood levels. A research program adds an electronic monitoring device (MEMS-caps, AARDEX/APREX, Switzerland) and examines the use of azathioprine metabolites as predictors for non-adherence. Patients receive a thorough psychosocial evaluation to identify potential risk factors for non-adherence. Preliminary results indicate that an objective adherence detection method has to be incorporated into practice if non-adherence is to be reliably detected (clinicians' impressions and patients' reports are not sufficient). A risk factor for non-adherence, post-traumatic stress disorder, emerges as a potential target for intervention. It is possible to integrate a formal mechanism to assess adherence into the work of a liver/liver transplant clinic. We hope that the presented program will inspire clinicians in the community and other programs to regard the assessment and improvement of adherence to medications as an important goal in the management of children who had a transplant.