Electrokinetic (EK) soil remediation is a known powerful technology for decontamination of organic and inorganic pollutants or their combination. Classically, one- and two-dimensional (10 and 2D) EK cells have been utilized for remediation of a variety of co-contaminated soils. Preparatory to scale up or practical EK applications, in the present study, three-dimensional small-scale (3D) EK cells on the batch scale were tested for remediation of petroleum-oil- and heavy-metals co-contaminated soil. In the results, with 0.10 M KH2PO4 as the anolyte for 21 days, removal efficiencies of better than 95% of TPH, more than 50% of As species and similar to 20% of Cu species were achieved, though the removal of the Pb and Zn species was relatively inefficient, at less than 20%. Currently, new electrolyte designs and a scaled-up EK cell operation are being planned for obtainment of data on real-soil-remediation feasibility (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.