The practical complications suffered by the most recognized electrochemical energy systems, such as, water-electrolyzers and metal-air batteries reside in the half-cell oxygen evolution reaction. To resolve this problem, continuous colossal efforts are required to develop the active, affordable and sustainable electrocatalysts. Shape-tailoring of the catalysts, constructed from non-noble metals is one of the emerging strategies to augment the activity of the material toward electrochemical reactions. In the present work, we demonstrate the template-assisted hydrothermal synthesis of hierarchical CoSnO3 hollow microspheres, constructible from the wafer-thin sheets of CoSnO3. The hierarchical CoSnO3 hollow microspheres possess a high specific surface area of 153.59 m(2)/g, and mesoporous configuration, which are the essential pre-requisites of an electrochemical system. In addition to this, the proposed CoSnO3 hollow microspheres possess adequate electroactive surface area (793.5 cm(2)) and happens to be a suitable candidate for driving the oxygen evolution reaction with a low overpotential of 282 my and Tafel slope of 96.5 mV/dec in alkaline medium. The higher turnover frequency (0.0045 s(-1)), high specific and mass activities (2.195 mA/cm(EASA)(2) and 28.752 mA/mg, respectively) were observed for CoSnO3 hollow spheres. Furthermore, the chronoamperometric measurement reveals a good stability of CoSnO3 hollow microspheres in alkaline condition, satisfying the fundamental demand of an energy system. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.