Insulin degludec is a new basal insulin analogue with an ultra-long duration of action that provides a flat and stable action profile with a duration of action greater than 42hours. Two clinical trials comparing insulin degludec and insulin glargine in basal-bolus therapy have recently been published. Both were 52-week, multicentre, randomised (3:1), treat-to-target trials in patients already using insulin. In both type 1 (n=629) and type 2 diabetes (n=1006), insulin degludec was non-inferior to insulin glargine with respect to reduction in HbA1c at 52weeks. There were also no significant differences between treatment groups with respect to fasting plasma glucose. At similar levels of glycaemic control, however, insulin degludec was associated with lower rates of hypoglycaemia than insulin glargine. In type 1 diabetes, overall confirmed hypoglycaemia (plasma glucose concentration<3.1mmol/L or severe episodes requiring assistance) was similar in the two treatment groups, but nocturnal confirmed hypoglycaemia (occurring from 00h01 to 05h59) was 25% lower with insulin degludec (P=0.021). In type 2 diabetes, overall confirmed hypoglycaemia was 18% lower (P=0.0359) and nocturnal confirmed hypoglycaemia was 25% lower (P=0.0399) with insulin degludec. Reductions in hypoglycaemia could reduce physicians' and patients' fears and encourage them to titrate insulin more aggressively, and to adhere more closely to treatment, with consequent better glycaemic control. The results of these trials suggest that insulin degludec has a place in the French clinical setting in basal-bolus therapy in type 1 and type 2 diabetes.