R.J. Mitchell and George Johnstone Stoney, Lord Rosse's assistants, discovered NGC 5088 on 18 Apr 1855. After reporting observations of NGC 5076, 5079 and 5077, another was found "12' nf (Pos 25° +/- from the north one [NGC 5077], pB, S, lE ns, pgmbM."

Heinrich d'Arrest found this galaxy on 26 Apr 1867, questioned if it might be LdR's nebula, and measured an accurate position. Truman Safford found it again on 20 May 1868 (he also questioned if his object was GC 3489 [NGC 5088]) with the 18-inch refractor at the Dearborn Observatory.

400/500mm - 17.5" (6/11/88): moderately bright, fairly large, very elongated 3:1 N-S, broad concentration. In a group with NGC 5077 13' WNW. Located 8' SE of mag 9.3 SAO 157863.

Notes by Steve Gottlieb