Silicone oil (polydimethylsiloxane, PDMS) was dispersed in water by virtue of stearic acid (SA)/triethanol amine (TEA) system as an emulsifier. Factors affecting emulsification of PDMS and utilization of such emulsion as a water-repellent finish for cotton/polyester fabric were investigated. The results revealed that the best formulation of such PDMS mother emulsion is PDMS (5%), TEA (2.4%), SA (4.5%), as well as equal molar ratio of AlCl3 and SA. Treating cotton/polyester fabric with 40 g/L of such emulsion followed by drying at 100 OC acquired that fabric with water repellency, softness, and stiffness properties accompanied with a decreasing in air permeability and coefficient of friction of the water repellent fabric. The TEM image indicated that such emulsion particles size ranges between 6 to 10 nm. The treated fabric surface was characterized via water contact angle and SEM as well as EDX analysis.