This study aims to investigate bacteria for biodegradation of oil pollutants from oily industrial wastewater to be used as bioremediation tools and to determine the characterization of bioremediation bioassays. A screening bioassay was carried out using six exogenous environmental bacterial strains to degrade oily pollution, which indicated promising clearance of the oily wastewater. Two strains, namely Enterobacter cloacae 279-56 (R4) and Pseudomonas otitis MCC10330 (R19), could successfully eliminate oil content and reasonable removal of the organic load. Results showed that the two promising bacterial candidates (R4 and R19) were selected according to the preliminary screening of the six tested bacteria considered the most efficient for all the tested parameters. The highest Removal Efficiency (Removal Efficiency resulted in Residual levels of total dissolved solids (TDS), biochemical oxygen demand, chemical oxygen demand, and Oil content in the treated oily wastewater effluents are 1940, 171, 131, and 84 mg/l respectively where these results are not within safe discharge limits, except for TDS. Hence, the bioremediation assays were carried out using the mixed culture since it was the most efficient strain for degrading all tested parameters.