Background: Over the past 20 years, solid organ transplantation has evolved from experimental treatments to an effective alternative for the treatment of various diseases, including heart failure. Treatment non-adherence is a limiting factor for the success of heart transplants. A systematic review of the evidence is needed to examine the effectiveness of interventions for managing adherence to treatment in heart transplant patients., Objective: The primary objective of this systematic review was to synthesize the best available evidence regarding interventions for managing adherence to pharmacological and non-pharmacological treatments in heart/heart-lung transplant patients., Inclusion Criteria: This review considered primary studies that included patients 18 years old or older, who had undergone heart or heart-lung transplantation (regardless of gender, ethnicity, comorbidities or whether they had received other treatments or not) who were receiving pharmacological and non-pharmacological treatments.This review considered studies that evaluated the effectiveness of interventions in managing adherence to pharmacological or non-pharmacological treatments among adult heart/heart-lung transplant patients. Primary studies comparing standard care with any type of intervention to maintain treatment adherence were considered.This review considered any experimental study design including randomized controlled trials; other research designs, such as non-randomized controlled trials and before and after studies, were also considered for inclusion.The primary outcome considered was patient adherence to pharmacological or non-pharmacological treatments by means of objective or self-report assessment., Search Strategy: Published and unpublished studies in English, Portuguese and Spanish were searched in electronic databases. Searches were completed in January 2014., Methodological Quality: Two independent reviewers, using the standardized critical appraisal instruments from the Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument, assessed methodological quality., Data Extraction: Data were extracted using the standardized data extraction tool from Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument., Data Synthesis: Statistical pooling was not possible due to substantial heterogeneity of the studies; therefore data were presented as a narrative summary., Results: Three quasi-experimental studies were included in this review. One study found that a dose reduction of immunosuppressive medications from a twice-daily to a once-daily regimen had a positive impact on treatment adherence; one found no significant difference in treatment adherence between patients who received educational intervention conducted in a teaching laboratory and those who received standard care; the third one also reported no significant difference in outcomes between a multifaceted intervention consisting of internet-based interactive workshops and standard care., Conclusions: The current best evidence to guide decisions regarding interventions to manage treatment adherence in heart transplant patients is limited. There is weak evidence that psycho-educational interventions (other than the standard care) has a positive impact on adherence and that decreasing the complexity of the treatment regimen by reducing the daily dose of the immunosuppressant drug improves adherence in heart transplant patients.