The large head is distinctively marked, with a long yellowish supercilium, blackish ear coverts, yellow eyering, and a black stripe down each side of the neck.

Young birds are brighter and ruddier above, lack the crown patch, and have a grey throat and breast shading to a whitish belly.

The subspecies Platyrinchus mystaceus insularis occurs only in Trinidad, Tobago, and Venezuela, with other forms differing in the brightness of the underparts or the crown colour.

It likes habitat with thick, tangled undergrowth and medium-sized trees with a canopy height of 33–100 ft (10–30 m), such as Elaeagia (Rubiaceae) and Hieronyma oblonga (Phyllanthaceae), overgrown with epiphytes and hemiepiphytes (e.g., Clusiaceae).

[3] White-throated spadebills are solitary, active birds, difficult to see as they rush through the undergrowth in search of small arthropods, their mainstay food.