Cryptocephalus sericeus can reach a length of about . The body of these little beetles is squat, cylindrical and almost oval. Elytra are irregularly punctured, not arranged in longitudinal rows. They do not completely cover the last part of the abdomen. Pronotum and elytra are golden green in males, while females show a metallic bronze color, with green-blue, orange or yellow reflections. The antennas are thread-shaped and relatively long. The head, the legs, and antennae are dark colored.
