Six species of the genus Stethantyx Townes are found to occur in Mexico. One species, S. mexicana sp. n., is described as new, and four recently described Neotropical species, S. alajuela Khalaim & Broad, S. heredia Khalaim & Broad, S. osa Khalaim & Broad and S. sanjosea Khalaim & Broad, are new records from Mexico. A key to species of Stethantyx occurring in Mexico is provided.