They are olive-backed with yellow undersides, a triangular orange-red throat and a white iris that stands out against the contrasting black head.

[4] Viscount Walden suggested that this had already been described by Jerdon as Brachypus rubineus and called the "ruby-throated bulbul" (although this name was published later).

[5] This was subsequently included as a subspecies of a larger number of similar bulbuls in the Asian region under a broadly circumscribed Pycnonotus melanicterus.

[6] With a resurgence in the application of the phylogenetic species concept, the isolated population in the Western Ghats of India was separated as the flame-throated bulbul.

[7][8] A 2017 study noted that the Western Ghats P. gularis and Sri Lankan P. melanicterus were closely related within a clade (the age of divergence from the common ancestor of its sister clades, however, has not been estimated in the study) that includes P. montis, P. dispar, and P. flaviventris leading to a placement of these species in a new genus Rubigula.

[9][3] The flame-throated bulbul is about 18 cm long with an olive-green back and yellow underparts, a squarish black head without a crest, an orange-red throat.