About 7, see text Thelaziidae is a family of spirurian nematodes, which form the mid-sized lineage of the superfamily Thelazioidea.

Like all nematodes, they have neither a circulatory nor a respiratory system.

[1] The subfamily Oxyspirurinae is monotypic, as are several little-known genera in the Thelaziinae; these all might not be valid.

All together, the systematic layout of this family is liable to change and cannot be considered more than tentative.

This Secernentea roundworm- related article is a stub.