Intermittently Scanned Continuous Glucose Monitoring (isCGM) devices are increasingly being used in patients with type 2 diabetes mellitus (T2DM) on insulin therapy for their benefits regarding disease management. Evidence of isCGM use in patients with T2DM treated with basal insulin or oral antidiabetic drugs is lacking. The aim of this study was to assess the efficacy and safety of isCGM in this population. This was an observational, retrospective, real-world study enrolling patients with T2DM who were starting with the use of isCGM. Data from medical records (i.e. demographics, clinical characteristics, laboratory assessments, and isCGM metrics) were collected over three time periods (baseline, 3 and 6 months). The endpoints were glycated haemoglobin (HbA1c) changes, and changes in isCGM metrics as defined by the International Consensus from baseline to a 3-month and a 6-month follow-up. Overall, 132 patients were included (69% male; mean age 68.2±11.0 years; mean disease duration 19.0±9.3 years; 80% on basal insulin ± oral drugs at baseline; mean baseline HbA1c 8.1%±1.3%). The estimated mean change in HbA1c from baseline was statistically significant at three (-0.4±1.0%; p=0.003) and at six months (-0.6±1.3%; p<0.0001). No statistical differences were found in the mean change of the isCGM metrics. Intermittently Scanned Continuous Glucose Monitoring is effective and safe in improving glycaemic control in patients with type 2 diabetes treated with basal insulin or oral antidiabetic drugs.