In this study the pollutant removal from a textile dyeing wastewater has been investigated by using the electro-coagulation technique with iron electrodes. In order to obtain optimal values of the system state variables, a 33 full factorial experimental design was applied. The electro-coagulation (EC) process response was evaluated on the basis of COD removal and decolourisation values. The electrolysis time and density current were statistically significant for the COD removal and decolourisation. Based on the lettuce seeds (Lactuca sativa) and brine shrimp (Artemia salina), the lowest toxicity level was achieved in 5 min of electrolysis time. Due to the remaining high toxicity level above 30 min of electrolysis time, the EC process is not adequate to be used in a single effluent treatment, suggesting that this electrochemical process of up to 5 min could be used as part of a complete effluent treatment system. © 2009 Elsevier B.V. All rights reserved.