Cyriocosmus perezmilesi sp. n. from Bolivia, Beni province, is described, diag- nosed and keyed inside the inner group of Cyriocosmus Simon 1903 which is represented by species with reduced paraembolic apophysis in male palpal bulb structures. The new species can be distinguished from all other cogeners, ex- cept C. blenginii Pérez-Miles 1998, by uniformly coloured carapace and lateral four-striped pattern on abdomen. C. perezmilesi sp. n. differs from C. blenginii by presence of the reduced paraembolic apophysis and bicolour femora (reddish brown, distally black).