A monogeneric family containing only the genus Vayssierea and perhaps (subject to molecular testing) only a single species, Vayssierea felis.
The body of vayssiereids is very small, less than 5 mm crawling length and the mantle skirt is absent. The rhinophores are simple, smooth and contractile, but they lack sheaths. They have no oral tentacles, but there are sensory patches each side of the mouth. There are no gills, but with their small size gaseous exchange takes place through the integument.
The anus is situated halfway down the dorsum just to the left of the midline.
They have direct development. Vayssiereids feed on very small, shelled polychaete tubeworms belonging to the family Serpulidae, subfamily Spirobrinae.