The aim of study is to investigate the effect of current density and stirring speed in the treatment of poultry slaughterhouse wastewater (PSW) using electrocoagulation with aluminum electrodes. In the experiments, initial pH and current density were chosen between 3 and 7, and 0.5 and 2.0 mA/cm(2) respectively. The best removal efficiency has been obtained, when initial pH and current density were adjusted to 3.0 and 1.0 mA/cm(2), respectively. Increasing current density values decreased COD removal efficiency. The highest removal efficiencies of 85, 85, 81 and 71% were obtained with the current density of 0.5, 1.0, 1.5 and 2.0 mA/cm(2), respectively. Initial pH values of these removal efficiencies were 4.0, 3.0, 3.0 and 5.0. When experiments were performed to investigate the turbidity removal efficiency, it was found that current density of 1.0 mA/cm(2) provided 98% removal efficiency. Results obtained from the experiments where stirring speed of 100, 150 and 250 rpm were used showed the removal efficiency of 85. 90 and 75% respectively with the current density of 1.0 mA/cm(2). Results showed that electrocoagulation is a suitable method for treatment of PSW. Electrical conductivity of investigated wastewater was nearly 2860 mu S/cm, which caused energy consumption to be relatively lower. (C) 2011 Elsevier B.V. All rights reserved.