Introduction: Ocular trauma remains a leading cause of unilateral blindness in the working-age population. Penetrating injuries involving organic material, such as wood, carry an exceptionally high risk of infectious and vitreoretinal complications. Case report: We present the case of a 40-year-old patient with an open-globe injury of the left eye caused by impact from a fragment of a wooden board. Initial examination revealed a full-thickness, extensive corneal wound with iridodialysis and prolapsed iris tissue, ocular hypotony, and hemorrhagic choroidal detachment. During the primary procedure, the corneal wound was repaired, traumatic cataract extraction was deferred, and tetanus prophylaxis and antibiotic therapy were initiated. Due to the rapid development of intumescent cataract and fibrous proliferation, pars plana posterior vitrectomy with cataract removal was performed. The patient’s condition stabilized by the 15th week after injury. At 18 weeks, sudden deterioration occurred, presenting with hypopyon and reduced visual acuity (5/50); endophthalmitis was diagnosed. During urgent surgical revision, material was collected, from which Serratia marcescens – a rare and aggressive pathogen – was cultured. Treatment was initiated according to the antibiogram. Conclusions: The case illustrates the complex course of a severe open-globe injury. It shows that injuries involving organic material carry a risk of late, destructive endophthalmitis. The surgical strategy must prioritize primary globe closure, with prompt decisions regarding secondary procedures to prevent vitreoretinal complications and to preserve the eye from atrophy.