Aim: To evaluate the safety and effectiveness of a pilot program to control perioperative blood glucose in patients with diabetes. Methods: A pre-post intervention study was conducted in a 280-bed hospital in Spain. In the year 2008 we implemented perioperative insulin protocols aimed at blood glucose values from 80 to 180 mg/dL. Surgical patients with diabetes admitted on year 2009 (intervention group) were compared with a control group of patients with diabetes admitted for surgery on year 2007, matched 1:1 by traditional wound class. Results: We analyzed 96 patients. Implemented protocols were followed in 48% of patients intra-operatively and 75% of patients postoperatively. Patients in the intervention group had reductions in blood glucose at surgery 150 +/- 61 mg/dL vs. 172 +/- 53 mg/dL; <i>p</i> = 0.05), greater proportion of target glucose values throughout hospitalization (67% vs. 55%; <i>p</i> = 0.07), and reductions in the incidence of nosocomial infections after controlling for confounders (Odds Ratio: 0.20; 95% Confidence intervals: 0.06 - 0.72; <i>p</i> = 0.014) when they were compared with the control group: The incidence of hypoglycemia was similar between two groups (0.12% vs. 0.10%, <i>p</i> = 0.867), respectively. Conclusion: Although our protocol needs improvements to increase implementation it was useful to control blood glucose safely and for reducing nosocomial infections