The current study was conducted to investigate the convective heat transfer coefficient of a novel TiO2-CNT hybrid nanofluid through the shell-and-tube heat exchanger under a laminar flow and the effects of temperature and mass fraction on it. TiO2-CNT hybrid nanofluids were prepared using a new and modified hydrolysis technique. The thermal conductivity of the TiO2-CNT hybrid nanofluid and other thermo-physical properties were assessed. Results indicate that the effective thermal conductivity and heat transfer coefficient of the base fluid was influenced significantly and increased by the 0.2 wt% of this novel hybrid nanofluid in distilled water.