Grimmia curviseta Bouman is a moss species endemic to the Canary Islands in the North Atlantic Ocean, which has a very restricted distribution across the summit areas of Tenerife and La Palma islands. Using massive sequencing, we developed ten polymorphic microsatellite markers for this species. The pattern of microsatellite alleles per locus provides preliminary evidence that G. curviseta is allodiploid. The average number of alleles per locus ranged from 2 to 7, and observed heterozygosities varied from 0.022 to 1.000. A significant genetic differentiation was observed between the Tenerife and La Palma populations, suggesting that there are some limitations to dispersal. This set of microsatellites constitutes a valuable tool to investigate patterns of genetic diversity across the distribution range of G. curviseta, information that may eventually be used to establish conservation strategies for the species. Owing to the cross-amplification with the closely related species Grimmia montana Bruch & Schimp., our study also demonstrates the utility of these markers for population-level genetic analyses in the genus Grimmia.