﻿AbstractIn preparation for a full taxonomic revision of the Neotropical genera ofCostaceae(i.e.,Chamaecostus,Costus,Dimerocostus, andMonocostus), we present the description of 17 new species of NeotropicalCostusand one new species of the Neotropic endemic genusChamaecostuswith notes on their distribution and ecology, vernacular names (when known), and diagnostic characters for identification. Distribution maps are included for all species, and each description is accompanied by photographic plates illustrating diagnostic characters.