Endophthalmitis is a rare but potentially sight-threatening ophthalmic condition characterized by marked inflammation of intraocular tissues and fluids. Bacteria is the most common cause of postoperative acute infectious endophthalmitis of which Gram-positive (GP) bacteria is the predominant isolate which constituted 47% of all positive vitreous cultures in endophthalmitis vitrectomy study. On the other hand, Gram-negative bacteria constituted 11.5% with poor visual outcomes compared to GP cases due to the fulminant and destructive nature of such pathogens despite prompt and appropriate treatment initiation. In this report, we would like to share the three cases of acute postoperative infectious endophthalmitis caused by Gram-negative organisms and highlight the challenges that might be faced when dealing with such presentations.