Tight glycaemic control emerged on the scene of critical care in 2001. Surprisingly, not many confirmation trials have been published so far. The randomised controlled trial by De La Rosa and colleagues is a timely and valuable attempt to repeat the landmark Leuven studies. The failure to replicate the beneficial effects of tight glycaemic control may boil down to some less obvious defaults in the set-up of the trial despite a seemingly adequate study design. The incorporation of ample power calculations and strict adherence to glucose targets are essential to fairly compare studies on tight blood glucose control. Only if these basic conditions of study design are fulfilled can the effectiveness of the therapy be assessed.