DEDICATÓRIAExperimental study with random distribution in two groups (Intervention or Control), which assessed the health-related quality of life and medication treatment adherence of patients who were hospitalized to adjust the oral anticoagulation drug dosage, according to their participation in an educational group (Intervention Group -IG) or in routine care (Control Group -CG). The groups were also compared according to their general self-efficacy and presence of anxiety and depression symptoms at two times: upon hospitalization (T 1 ) and two months after discharge from hospital (T 2 ). The study was developed at a public hospital in the interior of São Paulo State, Brazil, from March 2011 till December 2012. In total, 113 patients were considered eligible for the study, randomized between CG (N=58) and IG (N=55). The randomization took place after the patients' stratification into low, medium and high bleeding risk, according to The Outpatient Bleeding Risk Index. The patients who participated in the educative program received individualized orientations, using illustrative material, during the hospitalization. After discharge, the orientations were provided through telephone contact during the first and fourth week. To assess the research variables, the versions of the Duke Anticoagulation Satisfaction Scale, Treatment Adherence Measures, Hospital Anxiety and Depression Scale and General Perceived Self-Efficacy Scale validated for Brazilian Portuguese were used. After two months of monitoring, 44 participants completed the followup in CG (75.8% of participants at T 1 ) and 38 in IG (69.1%). The data were assessed by means of descriptive statistics and comparison of means for the variables of interest between the groups (independent Student's t) and intra-groups (paired Student's t-test), upon the hospitalization and two months after discharge. The significance level adopted was 0.05. When comparing the patient groups that completed the follow-up or not, we found similarities in sociodemographic and clinical variables and related to the oral anticoagulation therapy. These similarities were also observed when comparing the control and intervention groups during the hospitalization. As regards the health-related quality of life, treatment adherence, anxiety and depression symptoms and self-efficacy, the results reveal similarities between CG and IG at T 1 and T 2 , not confirming our study hypotheses for T 2 . At T 2 , the differences in the HRQoL (p=0.65), adherence (p=0.89), anxiety (p=0.20), depression (p=0.27) and selfefficacy (p=0.65) scores could not be confirmed when considering the participation in the educative program. In view of the results obtained in the present study, we conclude that, for patients with previous experience in oral anticoagulation treatment, the educative strategy used was not efficient to improve the selected response variables. From the clinical viewpoint, this result is relevant for the health professionals who deliver care to this population of oral anticoagulation drug user...