To provide a silicone rubber composition for wiper blades, which, due excellent moldability and ability to closely repeat the shape of the die during extrusion, is suitable for forming wiper blades of complicated shapes; to provide a method of manufacturing the aforementioned composition. A silicone rubber composition for a wiper blade comprising (A), a polydiorganosiloxane, (B) a finely divided, reinforcing silica filler, (C) orthoboric acid or metaboric acid, (D) a powdered calcium carbonate, (E) an organic peroxide curing agent, and an additive for improving water-repellent properties of a wiper blade made from said composition, comprising one or both of (F) a polyorganosiloxane having a viscosity of 1 to 10000 mPas and containing in one molecule at least two silicon-bonded hydrogen atoms and (G) a polydiorganosiloxane having a viscosity of 1 to 10000 mPas; a method of manufacturing the aforementioned composition.