Species in the family Pleurobranchidae have a prominent mantle and an internal shell that becomes reduced or is lost completely in adults.

Larval pleurobranchids can be planktotrophic (feeding on plankton), lecithotrophic (deriving nutrition from yolk), or direct developing.

Like all Pleurobranchomorpha, they breathe through an external gill, located on the right side (contrary to nudibranchs who have it on the back), just after the genital organ.

Many species produce secretions from their rich glandular mantle as a chemical defense against predators.

However, in the taxonomy of Bouchet & Rocroi (2005), the family Pleurobranchidae was placed in the superfamily Pleurobranchoidea, the only family belonging to the subclade Pleurobranchomorpha (sister to the subclade Nudibranchia), part of the clade Nudipleura.