Methoxyfenozide is a lepidopteran-specific insecticide belonging to non-steroidal ecdysteroid agonists. Its effects were evaluated under laboratory conditions on the morphometry and histology of ovaries in the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae). Treatment at LD₅₀ (0.01 µg/pupa) and LD₉₀ (0.37 µg/pupa) was made by topical applications on newly ecdysed female pupae. The compound was found to increase the size of the ovaries and to reduce the thickness of the follicular epithelium compared to controls. Moreover, the histological study of ovaries showed alterations including vacuolation, the absence of nurse cells, and shrinkage, leaving a space around the oocyte tissue.