The Caribbean genus Pseudophoenix (Arecaceae) has its center of taxonomic diversity in Hispaniola (Haiti and the Dominican Republic). Three species (P. ekmanii, P. lediniana, and P. vinifera) are restricted to this island. In this thesis I investigated the population genetic diversity and structure of Pseudophoenix using ten microsatellite loci. Results showed homozygote excess and high inbreeding coefficients in all populations across all polymorphic loci. Overall, there was high differentiation among populations. Results from the Bayesian and Neighbor Joining cluster analyses identified groups that were consistence with currently accepted species delimitation. We included the only known population of an undescribed morph from the Dominican Republic that has been suggested to represent a new species. Results from the cluster analyses suggested that this putative species is closely related to P. sargentii from Turk and Caicos. Our study provided insights pertinent to the conservation genetics and management of this genus in Hispaniola.