AIM The study tested the hypothesis that doctors using an insulin information checklist during simulated insulin initiation would impart more information regarding insulin use. METHODS A total of 128 simulations were conducted. Doctors (n = 64) were recruited from practitioners recently completing internship (n = 19) and those established in primary care (n = 45). Both groups of doctors were strata randomized to control (n = 32) and intervention groups (n = 32), so that each group contained equal numbers. Doctors in each group experienced two identical simulations of insulin initiation with an intervening period of 10 min. Doctors in the intervention arm were introduced to an insulin initiation checklist, which they reviewed independently and utilized in the second simulation. Trained assessors captured the provision of education in 21 predefined educational areas. Differences in the change of the total education provided between the first and second simulations were assessed using linear regression. RESULTS The difference in the mean change of education provided between the first and second simulations within the 21 educational areas for the control and treatment groups was 9.7 [95% confidence interval (CI): 8.8-11.1, P < 0.001] - an increase of 46.2%. The difference for the 15 areas relevant to pen use was 7.3 (95% CI: 6.2-8.4, P < 0.001) - an increase of 51.6%. CONCLUSIONS The checklist resulted in doctors providing significantly more education applicable to syringe and insulin pen routes of insulin administration during simulations. Further research is needed on the checklist's impact on healthcare professionals and patient outcomes in the clinical context. (Clinical Trials Registry No: NCT02266303).