We describe for the first time the nests of the Wing-banded Wren (Microcerculus bambla), a little-known species of Trogoldytidae from northcentral South America. Two nests were discovered in French Guiana during the rainy season of 1999. Both nests were in abandoned termite mounds attached to the undersides of fallen trees. Chambers of the two nests were lined with a mat of dead leaf fragments. Each nest contained a single, well-feathered nestling that disappeared, possibly due to fledging, within a few days of nest discovery. Although we did not observe nest building, we suspect that other termitaria-nesting birds at our study site, such as Puffbirds (Bucconidae) or Jacamars (Galbulidae) excavated the chambers. Thus, both Microcerculus species with described nests, the Nightingale Wren (M. marginatus) and the Wing-banded Wren, apparently are secondary cavity nesters.