Recent years, wastewater treatment plants are producing huge amounts of primary and secondary sewage sludge. On the other hand, large quantities of cement kiln dust (CKD) were produced from cement factories with negative impacts on the environment. CKD is a considerable by-product waste material of the industrial process. At the time being, remarkable advances have been achieved in the management and reuse of CKD. Due to its high alkalinity, huge amounts, negative impact and abundant source; it is considered as non-controlled source of pollution. Reuse of CKD in presence of waste sludge has high potential as an additional low cost raw material, fertilizer, constructing material, adsorbent and improving sandy soil properties. In this study, CKD was used as chemical coagulant / flocculent sewage sludge and adsorbent for soluble pollutants as well as microbial disinfectants. The optimum operating conditions were adjusted using Jar test experiment and tested sludge was analyzed. Results showed that on addition 8.0 g/l CKD to primary sludge and 7.0 g/l to return activated sludge (RAS) achieved good efficiency for solids separation, BOD5, COD, PO4, and NH4; respectively. Under the effect of high pH value, it was also beneficial in heavy metals immobilization and minimization of metal solubility in the treated sludge matrix. Consequently, metal ions were precipitated as hydroxides. Moreover, all pathogenic and viral species were destructed including total and fecal coliforms.