Sodium fluoride was found to be a simple, mild and efficient catalyst for the synthesis of 2,4-disubstituted 1,3-thiazoles and selenazoles utilizing phenacyl bromides/3-(2-bromoacetyl)-2H-chromen-2-one and thiourea/phenylthiourea/selenourea in aqueous methanol at ambient temperature. Analytically pure products are formed within 1–3 min in excellent yields. Sodium fluoride was found to be a simple, mild and efficient catalyst for the synthesis of 2,4-disubstituted 1,3-thiazoles and selenazoles for phenacyl bromides / 3- (2-bromoacetyl) -2H-chromen-2-one and thiourea / phenylthiourea / selenourea in aqueous methanol at ambient temperature. Analytically pure products are formed within 1-3 min in excellent yields.