Novel fused 1H-benzo[f]chromen-indole derivatives were synthesized regioselectivly in good to high yields by triethyl amine catalyzed condensation of 3-cyanoacetylindoles, β-naphthol and aryl aldehydes in methanol under ultrasounic irradiations and conventional conditions. The easy work-up of the products, rapidity, and mild reaction conditions are notable features of this protocol. The antibacterial activity of the selected products was examined. Some products showed promising activities.