We present significant new information on the distribution and status of 138 speciesof birds from the Andean East Slope of Colombia, based upon fieldwork between1990 and 2000 at 28 sites from central Dpto. Boyacá south to the Ecuador border.The first Colombian specimens of two species (Campylopterus villaviscensio, NapoSabrewing; Myrmotherula spodionota, Foothill Antwren) are reported. Three othertaxa (Ocreatus underwoodii addae, Piculus leucolaemus leucolaemus andMyiophobus p. phoenicomitra), the first two sometimes considered species distinctfrom known Colombian forms, represent first reports from Colombia based uponsightings or photographs; we add several more sightings of two species (Pipreolachlorolepidota, Iridisornis analis) previously known from single sight records. Inall, we report 35 species from the Andean East Slope of Colombia for the first time,southward range extensions on this slope for 47 species, northward extensions for21, upward or downward altitudinal extensions for 19, filling in of major discontinuitiesin distribution for 22; for ten of the latter, known from very few reports, new informationindicates a continuous distribution and far greater abundance than previouslysupposed. Range extensions and previously undiscovered populations of severalrestricted-range, Vulnerable, Near-threatened and Threatened species help toemphasize the importance of implementing conservation measures in the face of the increasing colonization pressures and insecurity. Based on our observations, wepresent several recommendations for setting conservation priorities in this rich butstill relatively poorly known region