Percina sipsi is one of the two smallest species in the genus Percina, rarely exceeding 50 mm SL (P. brevicauda, maximum SL is 50 mm, see Suttkus et al. 1994). Percina sipsi is distinguished from all other described species of Percina by a combination of the following characteristics: absence of bright colors on body and fins of adults; no orange band in spinous dorsal fin; no broad vertical bands on body extending dorsally across the back joining those of the other side;

7–11 lateral blotches fused into continuous dark brown to black lateral stripe with undulating margins; lateral stripe continuous with large, somewhat quadrate basicaudal blotch that extends onto base of caudal fin rays; small, dark blotch on upper and lower portion of caudal fin base, dorsal blotch typically darker; body below

lateral stripe white to cream colored, without dark blotches, becoming dusky in breeding males; suborbital bar absent or very poorly developed; lateral line complete, typically no pored scales on base of caudal fin; males with row of modified scales on midline of belly and one or two modified scales between base of pelvic fins;modified breast scale absent; nuptial tubercles absent; anal fin of breeding males not excessively elongate; males without caudal keel as a ventral extension of the caudal peduncle; snout does not project beyond anterior margin of upper jaw; broad premaxillary frenum present; serrae on margin of preopercle absent; branchiostegal membranes very narrowly joined to overlapping (Ref. 58738).