Objective To examine the factor structure and construct validity of the Maternal Self-Efficacy for Diabetes Management Scale (MSED) in 135 youth (Mage=13.50 6 1.83 years), with type 1 diabetes mellitus. Method The study used exploratory factor analysis (EFA) to examine the factor structure and correlations to examine relationships among MSED factors and select parent and child diabetes-related health behaviors and outcomes. Results EFA identified an 11-item three-factor solution (v2 (25, n=133)=40.22, p<.03, RMSEA=0.07, CFI=0.98, TLI=0.97), with factors corresponding to parents' perceived ability to manage their child's diabetes (MSED-M), problem-solve issues surrounding glycemic control (MSED-P), and teach their child about diabetes care (MSED-T). Correlational analyses revealed significant associations between the MSED-M and MSED-T and parent-reported optimism and youth's diabetes-specific self-efficacy. The MSED-T was also associated with glycated hemoglobin and self-monitoring blood glucose. Conclusion Results provide preliminary evidence for the reliability and validity of a three-factor solution of the MSED.