Type 2 diabetes mellitus (DM) is characterised by worsening glycaemic control, even in the presence of pharmacological intervention. The risk of developing microvascular complications decreases with improved control of blood glucose; however, currently available treatment options, including diet and exercise, do little to alleviate progressive failure in glycaemic control. In patients who fail oral monotherapy, combination therapy with oral agents is frequently employed to control glycaemic levels. The thiazolidinedione product rosiglitazone has been shown to be effective in producing significant improvements in glycosylated haemoglobin (HbA1c) levels when combined with metformin. The results of two studies assessing the cost effectiveness of rosiglitazone in patients with type 2 DM were presented at the 18th International Diabetes Federation Congress [Paris, France; August 2003].