In preparing the family Rhamnaceae for an upcoming volume of Flora Mesoamericana, it became apparent, based on recent molecular work (Bolmgren & Oxelman, 2004; Bolmgren, pers. comm., 2013), as well as historical (Grubov, 1949; Kartesz & Gandhi, 1994), and personal morphological studies, that recognization of the genus Frangula Mill. is well supported. The emphasis of the current study has been on Mesoamerican species and four species from Mesoamerica, F. circumscissa A. Pool from Costa Rica, F. darienensis A. Pool from Panama, F. grandiflora A. Pool described from Honduras and also found in Chiapas, Mexico, F. pendula A. Pool described from Costa Rica and also found in Panama, and one species from Oaxaca, Mexico, F. inconspicua A. Pool, are published here as new. Four Mesoamerican species and two varieties published in Rhamnus L. are transferred to Frangula as: F. breedlovei (L. A. Johnst. & M. C. Johnst.) A. Pool [≡ R. breedlovei L. A. Johnst. & M. C. Johnst.], F. mcvaughii (L. A. Johnst. & M. C. Johnst.) A. Pool [≡ R. mcvaughii L. A. Johnst. & M. C. Johnst.], F. oreodendron (L. O. Williams) A. Pool [≡ R. oreodendron L. O. Williams], F. wendtii (Ishiki) A. Pool [≡ R. wendtii Ishiki], F. capreifolia var. grandifolia (M. C. Johnst. & L. A. Johnst.) A. Pool [≡ R. capreifolia var. grandifolia M. C. Johnst. & L. A. Johnst.], and F. discolor var. mesoamericana (L. A. Johnst. & M. C. Johnst.) A. Pool [≡ R. sphaerosperma var. mesoamericana L. A. Johnst. & M. C. Johnst.]. The following new combinations are made for five Mexican species north of the Flora Mesoamericana area: F. chimalapensis (R. Fernández) A. Pool [≡ R. chimalapensis R. Fernández], F. hintonii (M. C. Johnst. & L. A. Johnst.) A. Pool [≡ R. hintonii M. C. Johnst. & L. A. Johnst.], F. longistyla (C. B. Wolf) A. Pool [≡ R. longistyla C. B. Wolf], F. scopulorum (M. E. Jones) A. Pool [≡ R. serrata var. scopulorum M. E. Jones], and F. surotatensis (Gentry) A. Pool [≡ R. surotatensis Gentry]. Four South American species are transferred: F. acuminata (Maguire & Steyerm.) A. Pool [≡ R. acuminata Maguire & Steyerm.], F. chimantensis (Steyerm. & Maguire) A. Pool [≡ R. chimantensis Steyerm. & Maguire], F. marahuacensis (Steyerm. & Maguire) A. Pool [≡ R. marahuacensis Steyerm. & Maguire], F. neblinensis (Maguire & Steyerm.) A. Pool [≡ R. neblinensis Maguire & Steyerm.]. Rhamnus sphaerosperma var. longipes M. C. Johnst. & L. A. Johnst. (from Hispaniola and Puerto Rico) is transferred to Frangula and raised to the rank of species, necessitating the publication of the new name F. longipedicellata A. Pool. Lectotypes are designated for F. polymorpha Reissek, R. citrifolia Rusby, and R. riojae Perkins.