BACKGROUND: Postprandial Glucose Excursion (PPGE) control is one of the goals of diabetes therapy. Patients should count meal carbohydrates but it is often inaccurate. Automated Advanced Hybrid Closed Loop (AHCL) systems may overcome carbohydrate count mistakes and aid to improve PPGE control. OBJECTIVE: To evaluate the effect of switching from manual Sensor Augmented Pump (SAP) to AHCL on PPGE in Type 1 Diabetic (T1D) subjects. METHODS: In 15 T1D patients using manual SAP, the Area Under the Curve (AUC) after breakfast, lunch and dinner was calculated for two weeks before (T0), immediately (T1) and 3 months (T2) after switching to 780 G AHCL system. Total Daily Dose (TDD), Time Above/Below/In Range (TAR, TBR, TIR), BMI, A1c, lipid profile and Treatment Satisfaction Questionnaire (DTSQ) were considered. RESULTS: A significant reduction in AUC was observed for breakfast and dinner at T2 and for lunch and dinner at T1. TIR increased, while TAR and TBR reduced significantly from T0 to T1 and T2. For A1c, BMI and plasma lipids no statistically significant differences were observed, although A1c decreased from 7.2% to 6.8%. TDD increased significantly, due to the automatic correction boluses. DTSQ score at T2 was 33 (range 32–34, max 36). CONCLUSIONS: After switching to AHCL, PPGE decreased rapidly by automatic correction boluses, without weight gain. Meal management simplification and glucose control improvement were associated with high satisfaction scores.