The results of an experimental study on the effects of the flow of nanofluids (water-based suspensions of nanometer-sized solid particles) on metal surfaces are presented. Either different nanofluids (containing TiO2, Al2O3, ZrO2, and SiC, respectively) and different target materials (aluminum, copper, stainless steel) have been investigated, under similar operating conditions. Different behaviors were observed depending on the specific combination nanofluid-target material, which in some cases led to severe damaging of the tested target, thus highlighting the need for an adequate preliminary investigation of the possible interactions between the selected nanofluid and the apparatus materials, before its adoption as heat transfer fluid. (C) 2013 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.