The egg of Endrosis sarcitrella (L.) was studied by scanning and transmission electron microscopy. The egg is obovoid to ellipsoid (0.47 × 0.29 mm). The surface is marked by a faint reticulate pattern of polygonal cells, the discs of which have a slightly roughened texture. High magnification revealed that this texture is imparted by minute, closely-spaced sinuous ridges that form an intricate maze-like pattern over the entire surface of the egg. There are usually six micropylar canals opening into an anterior pit which is surrounded by a rosette of petal-shaped primary cells. The primary cells are in turn partially or completely surrounded by series of secondary and tertiary cells. There are relatively few aeropyles. These are in the form of shallow pits with openings around their peripheries. The chorion is thin (0.2–0.5 μm) but in general structure is similar to that of other lepidopteran eggs.