Abstract The efficient synthesis of sixteen 5-arylidene-2, 4-thiazolidinediones by aldol condensation reaction of 2, 4-thiazolidinedione, mono-and di-substituted arenealdehydes and KOH using ultrasound irradiation is reported. The desired compounds were obtained in a few min (10–30 min) with moderate to good yields (25–81%).