[2][3] The dusky nightjar was originally described as Antrostomus saturatus; that genus was later merged into Caprimulgus and later still restored to generic status.

It appears to be most closely related to the eastern and Mexican whip-poor-wills (A. vociferus and A. arizonae, respectively).

The adult male's upperparts are sooty black with fine reddish cinnamon spots and bars.

The dusky nightjar has a wide but scattered distribution through the highlands of Costa Rica.

[3] The dusky nightjar's breeding season appears to span from February or March into April.

The male dusky nightjar's song is "a trilled, double-noted whistle prurrr prureee or prurrrr prruwhip".