Ernodea Swartz (Tribe Spermacoceae) and Erithalis P. Browne (Tribe Chiococceae) are two genera of Rubiaceae that are endemic to the Caribbean, composed of four and nine species, respectively. Molecular phylogenies were analyzed in a biogeographic context using Brooks Parsimony Analysis (BPA) and Fitch Parsimony methods. A geographic association of Cuba and Dominican Republic was supported by area cladograms generated by BPA for Erithalis and by the combined data matrix. Additionally, the two parts of Hispaniola (Dominican Republic and Haiti) appear in two different places on the cladogram suggesting that Hispaniola represents a composite of geological areas. Fitch analyses support a Greater Antillean origin for Erithalis, however, it was ambiguously resolved for Ernodea. Overall, biogeographic analyses explain the present-day distribution of Ernodea as a product of dispersal, whereas a combination of vicariance and dispersal events appears to be involved in Erithalis biogeographical history. In general, the study implies that trans-oceanic seed dispersal plays an important role in the distribution of these genera, in addition to Tertiary vicariance events for Erithalis.