INTRODUCTION In critical situations, such as the current COVID 19 pandemic, themes of fear, uncertainty and stigmatization are common and constitute barriers to appropriate medical and mental health interventions. These challenges, when faced by those who live with a chronic disease, such as diabetes mellitus (DM), can negatively influence quality of life and adherence to treatment, compromising the control of the disease. OBJECTIVES The present study aims to investigate the effectiveness of a tele-intervention during the COVID-19 pandemic in improving glycemic control, lipid profile, blood pressure levels and parameters of medication adherence, mental well-being and sleep quality in patients with type 1 DM and type 2 DM. METHODS A randomized clinical trial will be carried out with patients with a previous diagnosis of type 1 DM and type 2 DM, who are registered at the Hospital de Clínicas de Porto Alegre (HCPA). Inclusion criteria will be age greater than or equal to 18 years, collection of HbA1c in the HCPA laboratory in January, February or March 2020 and availability to receive weekly phone calls. Patients will be randomized, stratified by type of diabetes, in two groups: G1: participants will receive a tele-intervention by a case manager weekly to discuss topics related to diabetes management and mental well-being during the social distancing period ; G2: participants will receive the usual care. The primary outcome assessed will be the variation in HbA1c levels comparatively between groups, with or without a tele-guided strategy, after four months of social distancing (or as long as the recommendation of social distancing measures remains). Secondary outcomes will include experiencing confirmation of COVID-19 infection, variation in lipid profile, blood pressure levels and variation in parameters of emotional distress related to diabetes, eating disorders, medication adherence, symptoms minor psychiatric disorders and altered sleep patterns, which will be evaluated with specific and validated scales. According to the sample calculation, 150 patients will be included in the study (92 with type 2 DM and 58 with type 1 DM). Analysis by intention to treat will be performed separately for patients with type 1 DM and with type 2 DM. SCHEDULE The proposed experiment will start immediately after approval of this project by the research ethics committee. The duration of the proposed intervention is 4 months (or as long as the recommendation of social distancing measures remains. This means that the study may be completed before or after that period, based on national recommendations for social distancing in Brazil), with a data analysis plan and publication of the results until September 2020.