Objective: To investigate glycemic control with hybrid closed-loop (HCL) in patients previously treated with multiple daily injections (MDI) or insulin pump in adults with type 1 diabetes (T1D) in clinical practice. Research design and methods: We retrospectively collected HbA1c values in adults with T1D using MDI or insulin pump (baseline) and 6±3 months after the switch to HCL. Results: During routine in-clinic visits, thirty T1D patients were switched to HCL. Baseline mean (SD) age was 46.6 (14.9) years, HbA1c was 8.0±1.5% (64±19 mmol/mol), 53% were women, and 60% used MDI (n: 18). HCL reduced HbA1c in the whole cohort (8.01±1.47% vs 7.15±0.70% [64±19 vs 53±9 mmol/mol]; p<0.05). For MDI treated patients, HbA1c was significantly lower after HCL implementation (7.79±0.92% vs 7.18±0.78% [64±12 vs 54±10 mmol/mol]; p<0.05) while in insulin pump treated subject the HbA1c decrease did no reach statistical significance (8.31±2.01% vs 7.12±0.62% [66±26 vs 54±8 mmol/mol]; p=0.628). Conclusions: In adults with type 1 diabetes in a single center real-world setting, HCL improved HbA1c in a clinically significant manner. When analyzing splitted data, only previous MDI treated subjects reach a statistically significative difference in HbA1c. Despite a similar decrease in HbA1c, given the small number of patients treated with insulin pump, the HbA1c improvement was not longer significative in this subgroup.