Here, we describe nests, eggs, and nestlings of the monotypic Star-throated Antwren, Rhopias gularis (formerly Myrmotherula gularis), found at Carlos Botelho State Park, in Atlantic Forest in the state of São Paulo, Brazil. Nests were pensile cups of dark rootlets and black fungal hyphae, found near forest streams, 34–70 cm high, over ground or water. A leaf appeared to form a roof over two nests. Clutch size was always two eggs, white with reddish and dark brown spots and blotches. Hatchlings were naked with pinkish skin. Nest architecture, eggs, and nestlings were similar to other Myrmotherula and Epinecrophylla, suggesting that nesting characteristics may not be informative to reconstruct recent DNA-based phylogenies that resolved the monotypic genus of this Brazilian Atlantic Forest endemic species.