The filamentous scorpionfish was first formally described in 1938 by the American zoologist Henry Weed Fowler with the type locality given as off Linao Point in Davao Gulf in the Philippines.

The specific name filamentosus means "filamented" and likely alludes to the thin flaps on the head and body.

[4] The filamentous scorpionfish has a strongly compressed body[5] with large head a which has a concave upper edge to its snout.

There are flaps of skin on the snout, chin, lower cheek, margin of the preoperculum and above the eye.

[1] The filamentous scorpionfish is found in the Indo-West Pacific region and has been recorded from Bali, Sulawesi, the Timor Sea, Philippines, Papua New Guinea and Japan.