We studied the habitat association of Band-tailed Antbirds (Hypocnemoides maculicauda) in four forest types in the Brazilian Pantanal between 1999 and 2006. Birds were sampled with standardized mist nets during 20 months and point count censuses during 14 months. Band-tailed Antbirds exhibited a preference for seasonally flooded forests (Landi and Cambarazal) with no capture or detection in drier forests (Cordilheira and Carvoeiro), even during the wet season. We found no evidence of regular local movements between different forest types. The 21 recaptures were normally in the same forest patch as capture, indicating strong site fidelity and defense of year-round territories. The 10 nests observed were pouch shaped and constructed with plant fibers; each contained two eggs. Nests were found between January and April when the Pantanal is flooded. The unusual breeding season of the Band-tailed Antbird appears to be closely associated with the flooding regime.