Insulin adsorption onto infusion equipment may affect glycaemic control. The change in insulin concentration during delivery through tubing employed for adult ICU and neonatal patients was determined using continuous flow UV analysis. Insulin adsorption depended on tubing composition, dimensions and flow rate, being highest for neonatal polyvinylchloride tubing at low flow rates. In continuous insulin therapy, we should consider the nature of the infusion set and flow rate.