The electrocatalytic oxygen evolution reaction (OER) on iron based perovskites with composition La1-xCaxFeO3-delta (0.0 <= x <= 1.0) in alkaline solution has been investigated. The perovskite samples were synthesized by combustion method. Energy dispersive spectroscopy and X-ray photoelectron spectroscopy were used to determine the bulk and the surface composition, respectively. The X-ray diffraction and iodometric titration method were employed to examine the phases and the oxidation state, respectively. It was observed that incorporation of calcium (Ca2+) ions in the lattice of LaFeO3 decreases the lattice parameters and the cell volume systematically as evaluated by Rietveld method. Furthermore, increase in the degree of Ca2+ substitution from 0.0 to 1.0, increases the average oxidation state of iron from Fe3+ to Fe4+ in addition to creating oxygen vacancies. The evaluation of OER kinetics on a rotating disk electrode setup suggests that incorporation of Ca2+ decreases the activity initially (0.0 <= x <= 0.4), but further substitution increases the activity. The maximum activity was observed for x = 1.0. This change in the OER activity suggests an interplay between the bond lengths and angles, oxygen vacancy and the average oxidation state of Fe. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.