In this paper, a detailed thermodynamic equilibrium and efficiency analysis of the MnSO4/MnO water splitting (WS) cycle is carried out using HSC Chemistry software. By drifting the molar flow rate of inert Ar (<(n)over dot>(Ar)) and thermal reduction temperature (T-H), the thermodynamic compositions related to both thermal reduction (TR) and WS steps are identified. Moreover, the consequence of T-H, <(n)ver dot>(Ar), and WS temperature (T-L) on the process parameters associated with the cycle is also inspected. The obtained results denote that this cycle can attain a solar-to-fuel energy conversion efficiency () up to 45.3% if the TR and WS steps are conducted at 1573 K and 550 K, respectively. By employing heat recuperation up to 10, 30, and 50%, the eta(solar-to-fuel) of the MnSO4/MnO WS cycle can be increased up to 47.6%, 53.1%, and 60.0%, correspondingly. Based on the eta(solar-to-fuel) = 45.3%, the performance of the MnSO4/MnO WS cycle appears to be better than the formerly probed metal oxide based WS cycles. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.