Thermal-hydraulic characteristics of water based ZrO2 nanofluids has been investigated in a segmental baffled shell and tube heat exchanger in turbulent flow regime. The effect of Reynolds number, nanoparticle loading, mass-flow rate, and tube lay-out has been analysed on overall heat transfer coefficient. The effect of Reynolds number on the tube side pressure drop and convective heat coefficient have also been discussed. The effect of shell side mass-flow rate was also investigated on shell side heat transfer coefficient determined using Bell-Delaware method. The nanoparticle volume concentration is taken very low i. e. 0.2%, 0.4%, and 0.8%, respectively. The improvement in both tube side convective heat transfer coefficient and overall heat transfer coefficient has been observed. The maximum improvement in the convective heat transfer coefficient is found to be 14.1% for 0.8% ZrO2 nanofluids. However, the percentage enhancement in tube side pressure drop was higher than the percentage increment in the tube side heat transfer coefficient.