Three new species and a new name of Piper from the Amazonian slopes of the northern Andes are proposed and described. Piper cajambrense var. caquetanum, described from Caqueta in Colombia, is elevated to species rank under the name P. oteguanum and an emended description and an illustration are provided. Piper oteguanum is distinguished from P. cajambrense var. cajambrense by its glabrous leaves and petioles without epidermal warty outgrowths. The new species Piper rubrifolium has smooth internodes and petioles which easily distinguish it from the related species P. spoliatum and P. cajambrense, which has internodes and petioles with epidermal warty outgrowths and fruiting spikes less than 15 cm long. Piper caguanense differs from P. miguel-conejoanum by the smooth leaves that have evident idioblasts vs. leaves scabrous and without evident idioblasts. Piper laperdizense is distinguished from related species (P. brachypodon, P .dichroostachyum, P. dryadum, P. ottoniaefolium and P. cavendishoides) by its glabrous structures, leaves pinnatinerved from the lower third and with no evident idioblasts. Furthermore, three names of taxa from the east Andean slopes in Colombia are synonymized: Piper papillicaule under P. cuniculorum, Piper metanum var. villibracteum under P. mituense, and Piper calanyanum var. sardinanum under P. morelianum.