It is found in extreme eastern Bolivia, central to northeastern Brazil, and Paraguay.

[2] The specific name syphax is Greek meaning "sweet new wine" and alludes to the bright red color seen in the groin, belly, and ventral surfaces of the thighs and shanks in some living specimens.

Most specimens have a glandular dorsum with muted, tile-like dorsal pattern of darker and lighter browns.

[3] Leptodactylus syphax occurs in open areas, often rocky outcrops, in rock or termite cavities.

The tadpoles develop in standing bodies of water, such as quiet side pools of streams.