In comparison to other therocephalians, nanictidopids are relatively large, with skulls ranging from in length. Nanictidopids are characterized by their shortened skulls that appear triangular when viewed from above. The temporal region of the skull is very wide. Their skulls are similar to those of hofmeyriids, and the superfamily Nanictidopoidea has been established to unite these two groups. Nanictidopids have enlarged canine teeth in their upper and lower jaws, while the teeth behind them are very small. Small bumps and ridges cover parts of the upper and lower jaws. The parietal region at the back of the skull forms a sagittal crest. The postorbital bones that make up the back of the eye sockets are very thin, and sometimes do not enclose the entire socket. Unlike more advanced therocephalians, nanictidopids lack a secondary palate.
