This randomized controlled trial compared the use of an intensive and conventional insulin protocol on clinical outcomes in patients with severe sepsis and septic shock, in the first 72 hours. It was conducted at a university hospital in the city of São Paulo. Patients (n=46) were allocated into two groups: intensive glycemic (blood glucose between 80-110mg/dl) and conventional (180-220mg/dl). The Student's t-test and chi-square test were used for data analysis. A statistically significant (p<0.001) difference was observed in mean glycemia, but there was no difference in the variables of mean minimum arterial pressure (p=0.06) or maximum (p=0.11), serum creatinine (p=0,33) or in mortality (p=0.11). Although there was no difference between the groups regarding mortality, hemodynamic instability in the conventional group was longer and the only deaths occurred in it.