In this study, forced convective heat transfer characteristics of /water nanofluid flowing through a double pipe heat exchanger with plain twisted tape and cut twisted tape inserts is investigated experimentally to reveal the effect of cut twisted tape and nanofluid concentration on heat transfer. Experiments are conducted in a turbulent flow regime with Re number ranging from 4000-34000 and in the particle volume concentration range of 0<φ<0.1%.The results of thermal studies showed enhancement of convective heat transfer with nanofluids compared with flow of water. Also it was found that in higher Reynolds numbers the nanofluid has better heat transfer capability. The effects of twisted tape with and without cuts on edges on heat transfer coefficient and rate were investigated. It was found that the twisted tape with cut edges could enhance heat transfer rate better than twisted tape without cut edges. The pressure drop was investigated for flow of nanofluid and water. The results showed that there is a little difference between pressure drops in these cases. Friction factor and pressure drop in tube with plain twisted tape and cut twisted tape inserts are increased due to increasing flow resistance and contact surface between fluid and flow passage.