Aim: this work aims to assess if telemedicine and telemonitoring are clinically useful and safe for at-home monitoring of Coronavirus disease 2019 (COVID-19) patients. Methods: This is a retrospective cohort study of all patients diagnosed with COVID-19 in Galicia (Northwestern Spain) between 26 December 2020 and 15 February 2021. The structured, proactive monitoring via telemonitoring (TELEA) of patients considered to be high-risk in the Lugo, A Mariña, and Monforte Healthcare Area (ASLAM) was evaluated compared to other models in the remaining healthcare areas of Galicia. Results: Of the 47,053 COVID-19 patients, 4384 (9.3%) were in ASLAM. Of them, 1187 (27.1%) were monitored via TELEA, and the rest (3197 in ASLAM and 42,669 in the rest of Galicia) were monitored via other methods. Patients monitored in ASLAM via TELEA were older, consulted in the emergency department less frequently (p = 0.05), were hospitalized less frequently (p < 0.01), had shorter hospital stays (p < 0.0001), and had a lower mortality rate in their first hospitalization (p = 0.03). No at-home life-threatening emergencies were recorded. Conclusions: these data suggest that, for COVID-19 patients, a care model involving proactive at-home monitoring with telemedicine and telemonitoring is associated with reduced pressure on hospital services and a lower mortality rate.