Objective Sensor-augmented pump (SAP) therapy reportedly improves glycemic control and quality of life. However, there is limited information on changes in awareness of hypoglycemia and quality of life (QOL) after starting SAP therapy in Japanese patients with type 1 diabetes. The aim of this study was to evaluate glycemic control, awareness of hypoglycemia, and QOL after initiation of SAP therapy in these patients. Methods The study included 20 patients with type 1 diabetes who started SAP therapy. HbA(1c) levels, values derived from continuous glucose monitoring [including percentages of time in target range (70-180 mg/dL), time below range (< 70 mg/dL), and time above range (> 180 mg/dL)], the Diabetes Treatment Satisfaction Questionnaire score, and the Clarke score were compared between baseline and after 3 and 6 months of SAP therapy. Results There was a significant decrease in HbA(1c) at 3 and 6 months after starting on the SAP (p < 0.0001). There was also a significant decrease in time above range (> 180 mg/dL) at the two time points (p = 0.0069 and p = 0.0042, respectively). There was no significant change in time below range (< 70 mg/dL). There was a significant reduction in the Clarke score (p = 0.0347 and p = 0.0003, respectively) and a significant increase in the treatment satisfaction score (both p < 0.0001). There was no significant change in any of the three MOS 36-Item Short-Form Health Survey v2 component summary scores. Conclusion SAP therapy was associated with improvement of glycemic control, mainly by reducing hyperglycemia, and patients' satisfaction with treatment.