We recorded nectarivorous and frugivorous visitors of Marcgravia longifolia (Marcgraviaceae) at the Estación Biológica Quebrada Blanco in the northeastern Peruvian Amazonia. M. longifolia belongs to the subgenus Plagiothalamium, with downward facing flowers. A glossophagine bat, probably Anoura caudifer, was identified as a potential pollinator. Three primate species - Saguinus fuscicollis, Saguinus mystax and Callicebus cupreus - were recorded as potential seed dispersers. This is the first documentation of primate seed dispersal of a species from the family Marcgraviaceae.