BACKGROUND The effectiveness of human and analogue insulins is similar but the latter have more advantageous pharmacokinetic features, leading to an improvement in hypoglycaemia and come closer to achieving the physiologic insulin profile. OBJECTIVE To demonstrate that switching from a human basal-bolus insulin treatment to an insulin glargine-based basal-bolus regimen can achieve a better glycaemic control. METHODS This 3-month prospective, non-interventional study, including a 12-month retrospective data collection phase, enrolled patients who were switched to the insulin glargine- - 100 U/mL - based basal-bolus treatment at the time of enrolment if they were inadequately controlled and had at least one additional HbA1c result in the 12 months before the switch. Of 1513 patients 1181 had the data that were needed for the efficacy analysis. RESULTS The mean age of the efficacy population was 58.3 years and 48.1% were male. Their mean HbA1c levels remained unchanged in the year before the switch: it was 8.8 ± 1.4% at 12 months prior to the switch and 8.8 ± 1.2% at the switch, but decreased significantly to 7.7 ± 1.0% (p<0.001) after 3 months. Between the baseline and 3 months, the fasting blood glucose and the postprandial blood glucose improved significantly (from 10.0 ± 3.2 mmol/L to 7.4 ± 1.9 mmol/L, p<0.001 and from 11.1 ± 2.8 mmol/L to 8.8 ± 1.7 mmol/L, p<0.001, respectively). Insulin doses were increased both before and after the switch. CONCLUSIONS Switch to an insulin glargine-based basal-bolus regimen could achieve a significant improvement in the glycaemic control in patients who were inadequately controlled prior to the switch. Orv Hetil. 2018; 159(29): 1201-1207.