[2][3][4] Although generic allocation of this species has been controversial, molecular data have now confirmed its close relationship with Scarthyla goinorum and placement in that genus.

[3] Indeed, adults are very similar to Scarthyla goinorum; however, the male advertisement call and tadpoles are clearly distinct.

Night-time coloration is lime green with indistinct stripes; the ventral parts are transparent.

[5] The male advertisement call resembles a cricket chirp (and can be mistaken as such) and has very low intensity.

[5] Scarthyla vigilans occurs in open environments of lowlands, including flooded grasslands, degraded areas with low vegetation, and shallow standing water.