Indole skeleton is one of the most prevalent building units in wide range of biologically active and pharmacologically useful compounds including many natural products. Herein, we report a novel one-pot synthesis of N-acylindoles via tandem Paal-Knorr cyclization/annelation of primary aromatic amides. This new method involves the use of a solid acid catalyst and microwave irradiation under solvent-free conditions. The reaction proceeds in very short reaction times providing excellent yields and selectivities.