Neotropical freshwater crabs have a wide distribution range from southern Mexico to Peru, including the entire Amazon basin and the Guianas. Among them, highland species of the genus Microthelphusa Pretzmann, 1968, have a very peculiar biogeography. Their distribution is insular and discontinuous, presenting considerable separation between them. Twelve species are found south of the Orinoco River, of which six are found in the Venezuelan Guayana, and of these, five are endemic to the highlands of the tepuis. In this paper I attempt to explain the distribution of the species of Microthelphusa and their occurrence in the upper elevations of the tepuis.