OBJECTIVES: The Lack of Adherence to Immunosuppressive Treatment (LAIT) has been associated with Chronic Humoral Rejection (CHR) and decreased graft survival which can increase Health Resource Utilisation (HRU). Prevalence of LAIT has been reported to range between 7.4% and 41.8% of Spanish Kidney Transplant (KT) patients and published studies suggest LAIT may cause up to 20-50% of CHR episodes in Spain.  The objective of this study was to estimate the resource utilization associated with LAIT in KT   patients in Spain. METHODS: A systematic literature review was conducted using Medline, PsycINFO and BVS to identify Spanish studies published between 2009 and 2013 focusing on KT and LAIT. Following the review a questionnaire was developed to explore HRU associated with LAIT.  Six national experts in KT from Spain completed the survey and the data was analysed using Computer Assisted Qualitative Data Analysis (CAQDAS). HRU was estimated independently for suspected LAIT, suspected CHR, confirmed CHR and graft loss. RESULTS: Suspected LAIT and CHR were associated with additional HRU quantified by additional nephrologist visits, heightened immunosuppressive blood-level monitoring, and 2 measurements of anti-HLA antibodies (Luminex), 1 ultrasound scan and 1 kidney biopsy. Confirmed CHR was associated with additional HRU such as increases in the number of follow-up visits from 1 visit every 4-6 months to 1 visit every 1-2 months, associated monitoring and testing (bloods, ultrasonography, donor-specific antibodies, proteinuria). A proportion of these patients are treated with intravenous immunoglobulin, rituximab and plasmapheresis, and kidney biopsy to check whether CHR is resolved. Finally, most CHR episodes, up to 60%, cause graft loss with increased HRU associated with intensive patients’ follow-up to prepare the return to dialysis and renal replacement therapy. CONCLUSIONS: The lack of adherence to immunosuppressive treatment may lead to CHR and graft loss with an associated increase of healthcare resource utilization.