The behavior of voltammograms in square wave voltammetry in the presence of a significant ohmic potential drop for reversible and irreversible simple electrode reactions has been investigated. It is shown that the effects of ohmic potential drop can be drastically reduced by choosing adequately the square wave amplitude. Zone diagrams are drawn to define the conditions for which peak currents and peak widths at half-height can be expressed by simple formulas without considering the occurrence of ohmic potential drop. It follows that square wave voltammetry can be properly implemented in low-conductive media or in molten salt media where high concentrations of depolarizer are used. (C) 2010 Elsevier B.V. All rights reserved.