Woodcreepers are insectivorous birds that eventually form feeding associations with other species to complement their energy intake. Here we present quantitative data on a possible commensal association between two woodcreeper species, the Eastern Olivaceous Woodcreeper Sittasomus griseicapillus and the Pale-winged Woodcreeper Dendrocincla turdina, and a Neotropical monkey, the Black-faced Lion Tamarin Leontopithecus caissara, at Superagui National Park, Brazil. Our aim is to bring new information on bird/monkey associations in order to achieve a better understanding of the functional basis leading to the occurrence of these associations. We never observed the two woodcreeper species following monkeys at the same time and we found a significant difference between the mean height in which each bird species associated with monkeys. We did not observe interspecific aggressions between woodcreepers and monkeys. Birds benefited from flushed prey, and we did not find evidence that monkeys have benefits or incur costs due to their association with birds, suggesting that these associations may be characterised as a form of commensalism. —Moro-Rios, R.F., Silva-Pereira, J.E., Ludwig, G. & Gomes Barriento, F. (2018). Interspecific association between two Woodcreeper species (Dendrocolaptinae) and a group of Black-faced Lion Tamarins (Primates, Callitrichinae). Ardeola, 65: 299–304.