Objectives: Comparison of continuous subcutaneous insulin infusion (CSII) with multiple daily injections (MDI) in achieving glycemic control in youths with type 1 diabetes mellitus (T1DM). Methods: Retrospective cohort study including 2 matched groups of youths with T1DM treated by CSII or MDI in a tertiary specialized children’s hospital in Saudi Arabia. Children and adolescents aged up to 18 years, diagnosed with T1DM and using CSII or MDI, from the period 2016 to 2018. Patients on MDI were newly-diagnosed patients with T1DM who had the disease for only 1 year duration; all CSII patients had at least 1 to 2 years of T1DM but who had just started on pumps in the past 3 months. We excluded patients with other autoimmune diseases, non-ambulatory patients and those admitted to hospital for non-diabetes reasons. Primary outcome was HbA1c at 1, 2, and 3 years, with weight gain as a secondary outcome. Ambulatory glycemic profile was analyzed from a subset of patients using intermittently scanned continuous glucose monitoring (isCGM). Results: A total of 168 youths with T1DM (n = 129 in the MDI group, n = 39 in the CSII group) were included. The CSII group consistently had lower HbA1c levels compared to the MDI group throughout a 3-year follow up period: 8.1% versus 10.1, P-value < .001 at 1 year, 7.5% versus 10.1% at 2 years, P-value < .001, 8.9% versus 10.3% at 3 years, P-value = .033. Body mass index significantly increased in both groups at 1 year, although greater in CSII group. In a subgroup using isCGM (n = 37 on MDI and n = 29 on CSII), the CSII group had a lower average blood glucose (194 mg/dL vs 228 mg/dL, P-value = .028) and a lower estimated HbA1c level (8.4% vs 9.6%, P-value = .022). Conclusion: Treatment with CSII resulted in lower HbA1c compared to MDI in our cohort, which was sustained over a 3-year period.