It is endemic to southern Brazil and is known from the eastern Paraná, Santa Catarina, and northeastern Rio Grande do Sul states.

[1][2] Before Sphaenorhynchus caramaschii was described in 2007, all Sphaenorhynchus from the south of the state of São Paulo state all way south to Rio Grande do Sul were identified as S.

There is a dark dorso-lateral line running from the snout almost to the groin.

[4] Males call from the floating vegetation during the hot, rainy season.

[3] The species' natural habitats are low bushes surrounding large permanent lakes at elevations of 100–1,200 m (330–3,940 ft) above sea level.