The aim of this study was to investigate the effects of iron (Fe) application against cadmium (Cd) toxicity on growth parameters, as well as superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and malondialdehyde (MDA) levels in lettuce plant and soil. In the field experiment, 20 kg Cd ha(-1), 80 tone ha(-1) sewage sludge, 50 kg and 250 kg Fe ha(-1) iron were applied. According to field experiment results, 20 kg Cd ha(-1) application did not result in a significant decrease in crop yield. APX and SOD activities demonstrated a significant increase in response to Cd toxicity; whereas SOD activity revealed a substantial decrease in Fe and sewage sludge applications. Cd application significantly increased the amount of DTPA-Cd in soil and plant. 50 kg Fe ha(-1) application to Cd-contaminated soil decreased DTPA-Cd level in soil. In comparison to Cd alone application, sewage sludge treatment in Cd-applied parcels decreased Cd concentration in soil and plant. It is concluded that Fe can be utilized in alleviation of Cd toxicity. Additionally, due to the low amount of heavy metal in urban sewage sludge, it did not show a severe toxicity effect and can inhibit Cd intake because of its organic matter content.