A room temperature curable organopolysiloxane composition for protecting electric/electronic parts is disclosed. The composition comprises: (A) an organopolysiloxane having a viscosity at 25° C. of 20 to 1,000,000 mPa·s and having at least two silicon atom-bonded hydroxyl groups or silicon atom-bonded alkoxy groups in a molecule; (B) an alkoxysilane represented by the following general formula or a partial hydrolysis condensation product thereof: R1aSi(OR2)(4-a) wherein R1 is a monovalent hydrocarbon group having a carbon number of 1 to 12, R2 is an alkyl group having a carbon number of 1 to 3, and subscript “a” is an integer of 0 to 2; (C) a mercaptobenzothiazole based compound; (D) zinc oxide powder and/or zinc carbonate powder; and (E) a catalyst for condensation reactions. The composition and/or a cured product thereof can protect electric/electronic parts from corrosive gases such as hydrogen sulfide gas and sulfuric acid contained in the atmosphere.