The present study was undertaken to record the variations of the posterior border of the sternum of the New World suboscines, in an attempt to determine the reliability of this area of the sternum as a taxonomic character. The conclusions drawn from this survey (of 993 specimens) are that, within a broad range of variants, two basic kinds of sternal configuration are found: two-notched (Types 2-3-4, as defined), and four-notched (Types 5-6). The four-notched sternum is not confined to genera in the Rhinocryptidae and Conopophaga, as previously believed. Variations within the twoand four-notched sterna may not be considered taxonomically significant unless they can be shown to be consistent in a large series of specimens. In no case should a single specimen of a species be assumed to show the only sternal configuration of the species. The possible adaptive significance of the observed range of variation is briefly discussed, but no conclusions may be drawn until a functional analysis of the passerine sternum can be made.