Pachymerium is a genus of centipedes in the family Geophilidae found mainly in the west Palearctic region and in south Africa.

[1] Centipedes in this genus feature an elongate head, scattered coxal pores, and sternal pores in a pair of anterior groups and a posterior transverse band; the forcipular coxosternite is broad, and the ultimate article of the forcipule has a prominent basal denticle.

[1] The Chilean species Pachymerium armatum measures only 20 mm in length and has only 37 leg pairs,[2] the minimum number recorded in this genus.

[1] The Russian species P. minutum is also notable for its small size (only 17 mm in length) and its modest number of legs (39 pairs in each sex).

[5][4] The Cuban species P. cubanum and the large Turkish species P. serratum (measuring 50 mm and 78 mm in length, respectively) each can have as many as 79 leg pairs,[6][7] the maximum number recorded in this genus.