The steady state concentration and current occurring at a microdisk enzyme electrode when a product from an immobilized enzyme reacts with the electrode is derived. A closed form of an analytical expression of concentration for the full range of enzyme activities has been derived. A simple approximate analytical expression of current in terms of all dimensionless parameters for film thickness r(1)/r(0) and enzyme kinetic chi r(0) for all values of Michaelis-Menten constant is also reported. Available limiting case results are compared with our results and are found to be in good agreement. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.