This nudibranch has a black dorsum with large yellow-capped tubercles surrounded by pale blue or translucent white rings. Towards the edge of the mantle these tubercles become small and scattered, sometimes without any yellow caps. The rhinophores are yellow or orange. A distinctive feature is the presence of small, yellow-capped, tubercles at the edges of some of the large tubercles in the middle of the back, and scattered smaller tubercles between the larger ones. The underside of the foot is grey with a longitudinal black line. It is very similar to Phyllidia carlsonhoffi and Phyllidia madangensis.