LAPTOP (Lantus + Amaryl + metformin vs. premixed* insulin in Patients with Type-2 diabetes mellitus after failing Oral treatment Pathways) was a multinational study which compared the addition of once daily insulin glargine (IG, Lantus) with the oral antidiabetic drugs (OADs) glimepiride and metformin with twice daily 30% regular/70% human neutral protamine hagedorn (NPH) insulin (Actraphane 30) and no OADs in 371 type 2 diabetes patients over a 24-week period. IG plus OADs was seen to be significantly more effective in lowering glycated haemoglobin A1C (HbA1C) (-1.64% vs. - 1.31%). We undertook a cost minimisation analysis using data from the LAPTOP study to determine the relative costs of the two treatment regimens. Overall, the cost per patient for 24 weeks for the IG plus OADs group was £207.61 compared with £313.49 for biphasic insulin aspart (BIA), a difference of 34%. During the 24-week period of the study the cost of a 1% reduction in HbA1C was £126.59 for IG plus OADs and £239.31 for BIA only. A 1 mmol/L reduction in fasting blood glucose cost £97 with IG plus OADs and £142.50 with BIA. The cost of achieving an equivalent reduction in HbA1C was 34% less with IG plus OADs than twice daily BIA with no OADs.