Aim: To evaluate the effect of faster aspart over glycaemic variability in type 1 diabetes (T1D) patients treated with sensor-augmented pump (SAP) in a real-world scenario. Methods: Observational study with SAP-treated adult T1D patients treated with faster aspart for three months. The primary endpoint was the mean amplitude of glucose excursions (MAGE).Results: Fifty patients were treated with faster aspart. Eleven patients (23%) withdrew during the follow-up mainly due to worsening of diabetes control (9 patients). Mean age was 41.2 yrs. (range 21-59) and T1D duration 22.4 & PLUSMN; 10.0 yrs. Mean SAP treatment duration was 3.6 & PLUSMN; 3.1 yrs. We detected a reduction of-7.0 (95% CI -1.1, -12.9; p = 0.021) in MAGE at the end of the study. Other glycemic variability indices were also improved: standard deviation of mean interstitial glucose (-3 mg/dl; 95% CI, -1, -5; p = 0.01), CONGA4 (-2.2; 95% CI -0.3, -4.2; p = 0.029), CONGA6 (-2.6; 95% CI -0.6, -4.6; p = 0.011), GRADE (-0.5; 95% CI -0.1, -0.9; p = 0.022), HBGI (-0.7; 95% CI -0.2, -1.3; p = 0.013), J-index (-2.9; 95% CI -0.7, -5.0; p = 0.011) and MODD (-5.7; 95% CI -1.7, -9.7; p = 0.006). A slight reduction in mean glucose management indicator was also detected (-0.14%; 95% CI, -0.02, -0.27; -1.4 mmol/mol; 95% CI -0.1, -3.3; p = 0.03).Conclusions: In SAP-treated T1D patients, faster aspart insulin was associated with reduced glycaemic variability, but also a high percentage of dropouts due to worsened glycaemic control. NCT04233203. & COPY; 2022 SEEN y SED. Published by Elsevier Espana, S.L.U. All rights reserved.