The objective of this study was to determine the effects of nitrogen fertilizer sources of ammonium sulphate and municipal sewage sludge on yield, N content and uptake of the maize (Zea mays L.). Nutrient and heavy metals were determined in soil and plant. The experiment with three sludge rates ( 256, 513 and 1026 kg total N ha(-1) or 9.5, 18.0 and 38.1 t ha(-1) sludge), two nitrogen rates ( 80 and 160 kg N ha(-1)) and zero-N control were conducted on a clay loam soils under irrigated conditions in Eastern Anatolia region in Turkey. Treatments were arranged in a randomized complete block design with four replications. Yield, N content and total N uptake of maize increased significantly with sludge application. 9.5 t and 19.0 t ha(-1) sewage sludge applications did not significantly affect heavy metal content of leaf and grain. However, 38.1 t ha(-1) sludge applications increased leaf Pb and Zn. DTPA-extractable Cd, Cu, Fe, Pb and Zn concentrations of the soil increased at applications of 38.1 t ha(-1) sewage sludge, whereas applications of 9.5 t and 19.0 t ha(-1) sludge only resulted in elevated levels of Cu and Zn. We conclude that if sewage sludge is to be used in production of maize, applications rate up to 19 t ha(-1) could be accepted. However, this means also that the N requirement of maize crop is not covered by the sludge; therefore, the rest of nitrogen could be supplied as inorganic N.