The value of self-monitoring of blood glucose (SMBG) levels in patients with non-insulin-treated type 2 diabetes has been debated. OBJECTIVE To compare 3 approaches of SMBG for effects on hemoglobin A 1c levels and health-related quality of life (HRQOL) among people with non-insulin-treated type 2 diabetes in primary care practice. DESIGN, SETTING, AND PARTICIPANTS The Monitor Trial study was a pragmatic, open-label randomized trial conducted in 15 primary care practices in central North Carolina. Participants were randomized between January 2014 and July 2015. Eligible patients with type 2 non-insulin-treated diabetes were: older than 30 years, established with a primary care physician at a participating practice, had glycemic control (hemoglobin A 1c) levels higher than 6.5% but lower than 9.5% within the 6 months preceding screening, as obtained from the electronic medical record, and willing to comply with the results of random assignment into a study group. Of the 1032 assessed for eligibility, 450 were randomized. INTERVENTIONS No SMBG, once-daily SMBG, and once-daily SMBG with enhanced patient feedback including automatic tailored messages delivered via the meter. MAIN OUTCOMES AND MEASURES Coprimary outcomes included hemoglobin A 1c levels and HRQOL at 52 weeks. RESULTS A total of 450 patients were randomized and 418 (92.9%) completed the final visit. There were no significant differences in hemoglobin A 1c levels across all 3 groups (P = .74; estimated adjusted mean hemoglobin A 1c difference, SMBG with messaging vs no SMBG, −0.09%; 95% CI, −0.31% to 0.14%; SMBG vs no SMBG, −0.05%; 95% CI, −0.27% to 0.17%). There were also no significant differences found in HRQOL. There were no notable differences in key adverse events including hypoglycemia frequency, health care utilization, or insulin initiation. CONCLUSIONS AND RELEVANCE In patients with non-insulin-treated type 2 diabetes, we observed no clinically or statistically significant differences at 1 year in glycemic control or HRQOL between patients who performed SMBG compared with those who did not perform SMBG. The addition of this type of tailored feedback provided through messaging via a meter did not provide any advantage in glycemic control. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT02033499