[en] Different synthetic fabrics have been treated by different methods and formulations to umpart waterproof finishing. These methods include surface coating with formulations based essentially on polydimethylsiloxane, together with styrene or methyl methacrylate monomers and their corresponding oligomers (polymers) under the effect of accelerated electrons. The other methods include the gamma radiation graft copolymerization of polydimethyllsiloxane / methyl methacrylate formulation and the commercial compound Wacker 290 onto the same synthetic fabrics polyester, nylon-6 and cotton/polyester blend. Also, the synthetic fabrics were treated with commercial compound Wacker 290 under the effect of thermal curing. Moreover, the effect of these treatments on the thermal stability, mechanical properties has been investigated. The results showed that the waterproof properties, in term of water repellency and absorption, of the different fabrics depend to a great extent, on the type and content of the formulation, method of treatment and the compatibility between the fabric and used formulation. It was found that polyester fabric displayed the highest water resistance regardless of the used silicone formulation. These treatment inpress the crease recovery and has a little effect on the dyeing and thermal properties. In comparison, electron surface coating is the most effective method to impart waterproof finishing, while graft copolymerization needs high dose levels to obtain such property