IntroductionControlling postprandial glycemia (PPG) is important to achieve optimal glycemic control, but few studies have evaluated how often is measured and evaluated. ObjectivesTo evaluate how often patients on insulin therapy measure PPG and modify insulin doses accordantly. As secondary objectives, we evaluated the factors conditioning elevated PPG and associated issues. Material and methodsCross-sectional observational study based on a web-based survey from an unselected sample of adult insulin-treated patients. A p-value of < 0.05 was significant. Results1251 patients (68% women, 38.9 ± 13 years [mean ± SD], body mass index (BMI) 24.2 ± 4.2 kg/m2, diabetes duration 17.4 ± 12.8 years, insulin dose 38 ± 18 IU) participated, 1104 with autoinmmune disease (AD) and 147 with non-autoinmmune diabetes (NAD). 59% of patients had HbA1c ≤ 7%, 92.7% of patients with AD and 55.8% with NAD were attended by specialists (p < 0.001). People with AD did more often blood glucose monitoring (BGM) (p < 0.0001) and used continuous glucose monitoring systems (CGMS) (p < 0.0001). 90.1% with AD and 68.0% with NAD received instructions on measuring PPG (p < 0.001), and more with AD received specific training to change the treatment (87% vs. 61.2%, p < 0.0001) and were more proactive. However, more with NAD discussed their postprandial glucose levels with their healthcare team during clinical visits (92.5% vs. 74.1%, p < 0.0001). Regarding bolus administration, 88.6% with AD and 68.7% with NAD injected the insulin bolus before meals (p < 0.001). ConclusionsPatients with AD determine PPG more frequently. Diabetes type, follow-up setting, number of injections and CGMS use were the most important predictive factors for PPG measurement. Diabetes education programs should address how to best monitor PPG and appropriate corrective actions.