Inflammation at the level of the β cell appears to be involved in progressive β‐cell dysfunction in type 2 diabetes. We assessed the effect of blocking interleukin‐1 (IL‐1) by anakinra [recombinant human interleukin‐1 receptor antagonist (IL‐1Ra)] on β‐cell function. Sixteen participants with impaired glucose tolerance were treated with 150 mg anakinra daily for 4 weeks in a double blind, randomized, placebo‐controlled cross‐over study with a wash‐out period of 4 weeks. At the end of each treatment period, oral glucose tolerance tests (OGTTs) and hyperglycaemic clamps were performed. First‐phase insulin secretion improved after anakinra treatment compared with placebo, 148 ± 20 versus 123 ± 14 mU/l, respectively (p = 0.03), and the insulinogenic index was higher after anakinra treatment. These results support the concept of involvement of IL‐1β in the (progressive) decrease of insulin secretion capacity associated with type 2 diabetes.