Background: A previously published randomized controlled trial demonstrated that implementation of an electronic health record linked personalized clinical decision support (PCDS) tool within primary care clinics improved mean A1c and BP control. We subsequently implemented a modification of the CDS for expanded use with high cardiovascular risk adults (CV-PCDS) that also retained the decision support for glycemic control for patients with diabetes. Here we analyze the association between primary care provider use rates of CV-PCDS with diabetes performance measures in patients with diabetes. Methods: Using data from a cluster randomized trial in 2012-2014, we analyzed the association of CV-PCDS provider-specific use rates in March 2014 with diabetes performance measures 6 months later, using Pearson correlation coefficients. Performance measures included the proportion of a provider’s diabetes patients who (a) achieved A1c < 8%, and (b) achieved a composite measure of optimal diabetes care (ODC) that required simultaneous achievement of A1c < 8%, SBP < 140 mm Hg, LDL < 100 mg/dl, non-tobacco user, and ASA use for secondary prevention. Results: Providers (N=43) used the CV-PCDS tool at a mean of 82.1% of targeted encounters of adults with high CV risk (range across providers 36.0% to 100% of encounters). The mean percentage of the diabetes subgroup who achieved A1c <8% was 73.7%, and the percentage of patients who achieved the ODC goal was 46.8%. Pearson correlation coefficients between March 2014 CV-PCDS provider use rates and A1c and ODC performance measures in August 2014 were 0.16 (p= 0.31) and 0.24 (p= 0.12) respectively. Conclusion: In this high-performing health care system with high CV-PCDS use rates, there was a positive but non-significant association of provider use of the CV-PCDS tool and provider-level quality of diabetes care 6 months later. The generalizability of this finding to lower-performing care systems, and to providers with lower baseline quality of diabetes care remains to be determined.