45 species for which confirmation appears to be lacking, are reviewed in this paper. Some have undoubtedly occurred and only lack proper documentation; others (primarily migratory species) have the potential to occur but fall short of having the minimum required documentation, and still others (mostly sedentary or near-sedentary species) are highly improbable and are, no doubt, based on misidentifications. My placement of these species in the above categories (Table 1) is, of course, somewhat arbitrary, and to some degree reflects my consideration about their likelihood of occurrence. Until we learn more about patterns of dispersal, especially in the nocturnal, hard-to-identify, and easily overlooked species (e.g. owls, nightjars, and swifts), the assignment of birds to these various lists is tenuous. For example, I would never have predicted Flame-colored Tanager, Piranga bidentata, to have a resident population in Belize (Jones et al. 2000) before receiving a report from a highly competent observer and subsequently seeing it myself. Other mid-elevation species from the mountains of nearby Guatemala may yet prove to have small populations on one or more of the higher, unexplored peaks in Belize, but their presence remains undocumented.