The first report of the Speckled Blunt-headed Tree Snake ( Imantodes inornatus ) is presented for the Magdalena River valley, from the departments of Antioquia, Bolivar, Boyaca and Caldas in Colombia. Since these records correspond to the biogeographic Magdalena province, the known range for the species is expanded. In Colombia, this is a trans-Andean species found from the Pacific rainforests of the Choco region, through the northern portion of the Western and Central Andean ranges, to the middle Magdalena River valley.