It is now the only species assigned to the genus Gymnasio that was introduced in 1854 specifically for the Puerto Rican owl by Charles Lucien Bonaparte.

[8][9][10] The genus name combines the Ancient Greek gumnos meaning "bare" or "naked" with the Latin asio, a type of eared owl.

[11] A species endemic to the Virgin Islands was described in 1860 by George Newbold Lawrence under the binomial Gymnoglaux newtoni.

The taxon is probably extinct as surveys of the Virgin Islands conducted since 1995 have failed to detect any Puerto Rican owls.

Its facial discs have narrow light and dark brown bars; the supercilium and lores are white.

The putative subspecies G. n. newtoni certainly occurred on St. Croix, St. John, and St. Thomas in the Virgin Islands but has not been positively recorded there since the mid 1800s.

The Puerto Rican owl's territorial song is "a short, relatively deep, somewhat guttural, toad-like quavering trill...rrurrrrrrr."

It also makes "a soft cackling gu-gu and "a loud coo-coo"; the latter call provides the local colloquial name "cuckoo bird".

[1] Its disappearance from the Virgin Islands is thought to have happened because the native forests there were mostly cleared by the end of the nineteenth century.