Since having been cloned in 1984, IL-1beta has been the subject of over 22,000 citations in Pubmed, among them over 800 reviews. This is because of its numerous effects. IL-1beta is a regulator of the body's inflammatory response and is produced after infection, injury, and antigenic challenge. It plays a role in various diseases, including autoimmune diseases such as rheumatoid arthritis, inflammatory bowel diseases and type 1 diabetes, as well as in diseases associated with metabolic syndrome such as atherosclerosis, chronic heart failure and type 2 diabetes. Macrophage are the primary source of IL-1, but epidermal, epithelial, lymphoid and vascular tissues also synthesize IL-1. IL-1beta production and secretion have also been reported from pancreatic islets. Insulin-producing beta-cells within pancreatic islets are specifically prone to IL-beta-induced destruction and loss of function. Macrophage-derived IL-1beta production in insulin-sensitive organs, leads to progression of inflammation and induction of insulin resistance in obesity. We summarize the mechanisms involved in inflammation and specifically the IL-1beta signals that lead to the progression of insulin resistance and diabetes. We highlight recent clinical studies and experiments in animals and isolated islets using IL-1beta as a potential target for the therapy of type 2 diabetes.