Gasketed plate heat exchangers (PHEs) occupy a crucial position in the energy sector due to their efficient and compact design. A number of studies have focused on making the plate heat exchangers more efficient and compact, since energy usage increases day by day. Therefore, the idea of utilizing nanofluids, whose thermophysical properties are better than those of industrial fluids, have drawn the attention of researchers. An experimental setup was designed and constructed at the TOBB ETU Heat Exchangers Laboratory to investigate the effect of utilizing nanofluids in a plate heat exchanger. The experiments were performed with three different working fluids, namely, tap water and 1 and 0.5 wt.% Al2O3/water nanofluids in a hot cycle. For all cases, the flow rates were 100–450 L/h, and the experiments were repeated three times for accuracy. As a result of this study, new correlations for the Nusselt number and heat transfer enhancement rates were obtained. Moreover, the friction factor correlations were found for all cases, and the effect of nanofluids on the pressure drop has been revealed. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.