This paper presents a novel multilevel PWM inverter employing series-connected transformers in order to improve the waveshape of output voltage and to reduce its harmonics. The proposed 11-level inverter consists of three full-bridge inverter modules and their corresponding transformers. Among their inverter modules, one is used as PWM operation and the others as level generation. From a suitable selection of turns ratio of transformer, continuous output voltage levels were generated appearing an integral ratio to input DC source. Because of their series connection of transformers, output filter inductor is not necessary. The operational principles and analysis are explained, and it is compared with a conventional multilevel PWM inverter. The validity of the proposed system Is verified through the experimental results using a prototype.