An indigenous Pseudomonas sp., isolated from the heavily petroleum-contaminated soil and identified as Pseudomonas plecoglossicida, was evaluated for its aerobic cometabolic removal of mixture of two representative chlorinated aliphatic hydrocarbons (CAHs), cis-1,2-dichloroethylene (cis-DCE) and trichloroethylene (TCE), with BTEX/toluene provided as substrate in a laboratory-scale soil slurry. The aerobic simultaneous bioremoval of the cis-DCE/TCE/BTEX mixture was studied under different conditions. Results showed that the increased BTEX concentration from 400 to 600 mg/kg prolonged the bioremoval of BTEX. The cometabolism of cis-DCE and TCE was significantly greater when toluene was provided as growth substrate compared to the BTEX mixture as substrates. Additionally, the bioremoval of toluene in the treatment with toluene as sole growth substrate was higher compared to the treatment with BTEX mixture as substrate. Results would enhance the applicability of bioremediation technology to the mixed wastes-contaminated sites.