Telemedicine had a significant increase during the novel coronavirus (COVID-19) pandemic, which is still on course. In different parts of the world, healthcare units had to adapt their practice, and several assistance services were remotely delivered. The present study is a systematic review of studies that had applied telemedicine during the COVID-19 pandemic and had assessed its effects on the delivered care. We have covered a 1-year period in order to assess the initiatives developed during the pandemic time and that had already evaluated the effects of the telemedicine program that had been implemented. All the analyzed studies evidenced a positive effect of telemedicine in the treatment of different conditions, including chronic diseases, mental disorders and oncologic diseases. The real impact of the COVID-19 pandemic in the healthcare sector is still to be fully understood, and telemedicine implementation in different areas is one of its positive legacies.