: This article presents a detection method for an open-switch fault in cascaded H-bridge multilevel inverters (CHMIs). Recently, CHMIs were widely used in high-power systems. Therefore, the reliability of this topology has become an important factor. To improve the reliability, methods for detecting open-switch faults are required. The proposed method is based on the current path analysis according to zero-voltage switching states. The location of both faulty cells and switches can be detected from the current waveform and zero-voltage switching states. This method is applicable when using the level-shifted pulsewidth modulation (LSPWM), which is commonly used for a modulation method in CHMIs. The performance of the proposed detection method is verified by simulation and experimental results.