The authors have designed and developed a telemedicine-based service for the follow-up and monitoring of patients on oral anticoagulant therapy (OAT) that consists of two phases; the first involving self-testing and the second involving guided self-management. To evaluate the first phase of the protocol, a project was conducted with 108 patients, with a mean age of 72.7 years and a mean treatment time at the start of the study of 55.2 months, divided into two groups: telemedicine and control (conventional procedure). The degree of anticoagulation control was similar in the two groups: individual in-range international normalized ratios (59.2% vs 61.1%; p = 0.55) and individual time within target range (65.7% vs 66.4%; p = 0.85) showed no significant differences. The incidence of adverse events--death (5.5% vs 5.5%; p = 1.0), major hemorrhagic complications (0% vs 1.8%; p = 1.0), minor hemorrhagic complications (7.4% vs 3.7%; p = 0.67), and thromboembolism (1.8% vs 3.7%; p = 1.0)--was also similar, with no significant differences. Acceptability of the change, measured in terms of quality of life (SF-12 and Sawicki questionnaires) and anxiety (state-trait anxiety inventory questionnaire) at the beginning and end of the study period was higher in the telemedicine group, with statistically significant improvements in mental component summary (3.6 vs -6.2; p = 0.02), dissatisfaction (-0.8 vs 0.2; p = 0.001), stress (-0.3 vs 0.05; p = 0.03), limitations (-0.2 vs 0.3; p = 0.005), social problems (-0.1 vs 0.3; p = 0.03), and state anxiety (-2.5 vs 2.3; p = 0.04). Parameters related to costs, such as the mean number per patient of office visits due to OAT (1.7 vs 13.8; p << 0.001) and other office visits (10.1 vs 11.5; p = 0.028), were also more favorable in the telemedicine group, as were additional parameters that enabled an exhaustive evaluation of the service. The positive results obtained indicate that the second phase of the trial can be initiated.