PEM fuel cells are outstanding candidates for using in automotive uses and an effective energy technology for the future. One of the biggest challenges facing their commercialization is associated with thermal conditions of the cells. The essential function of a thermal management system is to maintain the set temperature and heat the stack and each of the membranes that it is made up off equally. This work deals with a numerical investigation of thermal improvement for a single cooling plate of a PEMFC. A 210 x 220 mm wide uniformly distributed parallel channel cooling plate with nineteen parallel microchannel of 1 x 4 x 112 mm was employed to cool PEMFC. The cooling plate was of carbon graphite material. Among those, the 𝑆𝑖𝑂2, 𝐴𝑙2𝑂3 and 𝑍𝑛𝑂 were utilised for the cooling of the sample. It uses simple geometry and modified geometry for simulation. The 0. The subject of the study is 5% volume concentration of 𝑆𝑖𝑂2, 𝐴𝑙2𝑂3 and 𝑍𝑛𝑂 in water. The heating pad is taken as the source term which has only one energy source of 1298701 𝑊/𝑚 3 and considered to be constant. About the boundary conditions, flow rate of water from the inlet was varied from 400 up to 2000 Reynold Number. This proved that at 2000 Reynold Number as compare to other nanofluid the thermal performance of 𝑍𝑛𝑂 nanofluid with modified geometry was higher. The thermal benefits, as seen in this work that 𝑍𝑛𝑂 nanofluid having altered geometrical structure, could make it more appropriate coolant fluid for the impending uses in PEM fuel cell.