Information on reproductive biology is limited for many tropical birds, despite the importance of these data in areas such as ecology, taxonomy, and conservation. Hafferia zeledoni belongs to the Thamnophilidae family and was only recently elevated to the species level, and consequently little is known about its ecology and natural history. We found and monitored a dome-shaped nest of this species during 30 days. It was located on a steep slope in a sub-Andean forest, and both male and female participated in the incubation and care of nestlings. Night incubation was only performed by the female, and even though she also incubated during day, it was the male who spent more time on the nest during that period. The eggs were white with reddish blotches, and they measured on average 27.8 ± 1.2 × 19.7 ± 0.1 mm and weighed 5.84 ± 0.17 g. The two nestlings were naked with black skin and weighed 5.64 and 5.60 g at hatching, increasing to 28.61 and 31.60 g prior to fledging. We monitored the incubation behavior during 17 days, and the nestling period lasted 14 days. We compared our results with other members of the longipes clade finding similarities that support the newly established phylogenetic relationships. Our study provides the first description of the nest, nestlings, and incubation behavior of Hafferia zeledoni, and it provides new information on nest architecture that supports the dome nest radiation in this clade.