Biological treatment of saline wastewaters in conventional systems usually result in low BOD removal performances because of plasmolysis of organisms. In order to overcome this problem a salt tolerant organism ( Halobacter halobium) was used along with activated sludge culture in an aerated percolator unit containing immobilized cells on ceramic particles. Percolator unit filled with ceramic particles was aerated externally for liquid recycle and also internally through perforated tubes located inside the column. The system was operated continuously with different microbial cultures at different salt concentrations and effects of microbial culture and salt concentration on the rate and extent of COD removal were investigated. Inclusion of salt tolerant bacteria in activated sludge culture resulted in high COD removal efficiencies especially at high salt concentrations such as 5%.