Pseudochromis fuligifinis is distinguished from congeners by the following combination of characters: dorsal-fin rays III,25–26, with last 2–9 rays unbranched; anal-fin rays III,14–15 (usually III,15); circumpeduncular scales 16; dorsal-fin origin to pelvic-fin origin 23.4–25.9 % SL; horizontal scale rows below anterior lateral line 11–13; and caudal fin with sub-basal dark grey to black half-moon shaped marking on the caudal fin, with distal portion of fin posterior to dark spot and to distal tips of elongated dorsal and ventral lobes of fin sooty black (Ref. 88961).

Description: Characterized by brown color on head, grading to mauve on body; faintly dusky dorsal and anal fins; caudal fin with yellow posterior margin; anterior lateral line scales 20-27; predorsal scales 14-18 (Ref. 90102).