Etheostoma cyanoprosopum is distinguished by the following characters: lateral line complete with 45 to 53 scales; 11 to 17 transverse scale rows ; 16 to 20 scales around the caudal peduncle 16 to 20 ; dorsal fin with modally 10 spines and 12 rays; anal fin with 2 spines and 7 to 9 soft rays; pectoral fin with modally 14 rays; nape, belly, and prepectoral area are scaled; breast naked in most specimens; nine lateral blotches of pigment on side of body, 8 to 10 dorsal saddles, a narrow suborbital bar; spinous dorsal fin with three distinct color bands in nuptial males; a distal-most thin turquoise band, a medial band of dark red, and a basal-most band of black spots; second dorsal fin with blue color on distal third and a more basal red band limited to the posterior two-thirds of the fin. Nuptial males possess a turquoise to darker blue color on the pelvic fins, caudal fin, and margin of the anal fin. A turquoise color on the breast extends to the underside of the head, snout, and cheeks. A pale white line extends along the lateral line to the middle of the second dorsal fin. Absence of a red ocellus in the first interradial membrane of the first dorsal fin in both males and females (Ref. 116751).