The study of the immature fonns of Pimeliaphilus zeledoni (tritooymph. deutonymph, protonymph.larva, prelalVa and egg) show differences in the externa! mOlphology, characteristic for all the different stages such as body size.s ize and shape of scutum, chaetotaxy, (type, number, disposition, distances and size) for the gnathosoma, ídiosoma and legs. The lífe-cycle of the female of P. zeledoni includes all the immature stages while in the male, the deuto and tritonymph are lackíng. There is a need for detailed descriptions of the ímmature of other species of Pimeliaphilus to establish oomparisons and differences amoog species.