We report the opportunistic predation of a female Common Scale-backed Antbird (Willisornis poecilinotus) entangled in a mist-net by a Goliath bird-eating spider (Theraphosa blondi) in the Brazilian Amazon. We suggest that the predation event occurred for the following combination of reasons: the spider is common in the study area; the bird became entangled at dusk, when the spider begins its activity; and the lowest mist-net shelf was suspended close to the ground. To reduce opportunistic predation events we recommend that it is critical to keep intervals between mist-net checks to a maximum of 15 min in Amazon forests. We also emphasize that attention is required when installing mist-nets to avoid nets touching the ground when animals become trapped in them.