OBJECTIVES: Noncompliance to immunosuppressive medication regimens in renal transplant recipients is an important factor affecting graft survival. The objective of our study was to examine the prevalence of noncompliance, to verify factors associated with this condition as well as to assess the long term impact of noncompliance on graft survival after renal transplantation in Latvia. METHODS: Noncompliance with medication and follow-up care was retrospectively evaluated in 311 adult renal transplant recipients (mean age 48.7±14.4 years, 48.2% female, 86.8% primary graft) with at least a 5 year follow-up period, using self-report questionnaires, clinician rating, 20% rate of missing outpatient visits and measurement of the amount of medication that remained unused (on account of pharmacists` report of non-received pills). Thus, our patient compliance data included considerations of natural environment. Long-term graft and patient outcomes in compliant and non-compliant patients were acute rejection rate and chronic allograft dysfunction, graft and patient one, three and five year survival. RESULTS: The prevalence of immunosuppressive medication regimen noncompliance in this patient setting was 6.1% and prevalence of appointment noncompliance was 7.1%. Noncompliant patients had more acute rejection episodes (P<0.05) and chronic allograft dysfunction (P=0.02). Risk of all cause graft failure in the noncompliant group was higher - OR 9.3 (95% CI 3.0-28.8; P<0.001) compared to the compliant group. Graft survival at one, three and five years was 88.3%, 81.3% and 75.7%, respectively, for compliant patients and 73.7%, 61.4% and 37.9% respectively for noncompliant patients (Log Rank 5.09; P=0.02). The risk factors associated with noncompliance was younger age (P<0.05) and a immunosuppressive regimen with the highest number of pills (P=0.02. CONCLUSIONS: Patients` compliance with medication and follow-up care after renal transplantation shows long-term clinical benefits. Thus, it is of utmost importance to develop intervention strategies to enhance compliance in this population.