Lawrence Parsons discovered NGC 5338 on 3 May 1877, along with NGC 5348, while making an observation of NGC 5356. He noted "about 20' p[receding] and 5' or 6' s[outh] is another, elongated p f, about 4' f a D*.". The bright pair of stars is 3.5' WNW. The same observation also mentions "a third neb is about 10' p and 5' +/- s" and this refers to NGC 5348.

400/500mm - 17.5" (4/28/90): fairly faint, fairly small, elongated 2:1 E-W, almost even surface brightness. Forms a right angle with a wide mag 10 double star (HJ 2690 = 10.6/11.4 at 27") 3' WNW and two mag 10/12 stars 3' NNE. First of 7 in the NGC 5363 group with NGC 5348 13' E.

Notes by Steve Gottlieb