OBJECTIVES: The objective of this study was to review the literature about adherence to warfarin treatment in Brazil. METHODS: A systematic review of the literature and a wide search in LILACS (Literatura Latino Americana e do Caribe em Ciências da Saúde) and MEDLINE (Medlars On Line) electronic databases were conducted to identify studies with the key words: “warfarin” and “Brazil”. The combination of terms was used as reference for the analysis. Search was restricted to randomized controlled trials (RCT), systematic reviews, meta-analysis and prospective clinical trials (PCT).  RESULTS: 77 studies were identified, from which only 22 met inclusion criteria: 1 meta-analysis, 5 RCTs, 8 systematic reviews and 8 PCTs. Only 1 study described adherence to treatment. From a total of 229 randomized patients, 119 received warfarin. Adherence to treatment was observed in 42% (p=0.001) of patients using warfarin considering an average of 57+-18 months of follow-up, INR < 2 in 37.54 % and INR > 2 in 11.18 %.  Multivariate analysis estimated that every 1% of INR <2, the risk of a thromboembolic event increases 8.4%.   CONCLUSIONS: The systematic review of the literature showed lack of data regarding Brazilian patients under warfarin treatment. The only available study did not define adherence and it did not investigate the underlying causes of non-adherence. Thus, it is recommended the conduction of further studies in order to provide better understanding of anticoagulant therapies compliance in Brazilian patients.