Polydimethylsiloxane composite membrane was employed for the separation of phenol and sodium chloride in synthetic wastewater. The major operational parameters affecting phenol transfer through this composite membrane were screened by the orthogonal array and range analysis. The results showed that the significance of parameters on the permeate flux followed the order of phenol concentration, membrane skin layer thickness, recirculation rate, and sodium chloride concentration after 6 and 48 h operations. Optimal operation range was determined by the response surface methodology coupled with central composite design. The higher was the phenol concentration in the influent or the thicker was the membrane skin layer thickness, the higher was the permeate flux throughmembrane. Also, the higher was the recirculation rate, the higher was the permeate flux through membrane.