Aims: To describe the aetiology and microbial susceptibility profile of endophthalmitis cases treated at an ophthalmological referral centre in Colombia. Material and Methods: A retrospective descriptive study was carried out with all endophthalmitis cases referred to the Fundación Oftalmológica de Santander FOSCAL (Floridablanca, Colombia) from 1 January 2012 to 31 December 2015. Results: 121 eyes of 121 patients were evaluated. 77.7% of them were male and the mean age was 42.9 years. Five of them (4.1%) corresponded to endogenous endophthalmitis, and 116 (95.9%) to exogenous endophthalmitis. Of the latter, 66.9% were associated with trauma (almost one-half of them associated with intraocular foreign body), and 29.5% with intraocular surgery. The most common isolated microorganisms in the exogenous endophthalmitis group corresponded to methicillin-resistant and methicillin-sensitive strains of Staphylococcus epidermidis and Staphylococcus aureus, which were mostly susceptible to imipenem, vancomycin and moxifloxacin and resistant to ceftazidime. Conclusion: Endophthalmitis is a potentially sight-threatening condition, especially in cases of inadequate treatment. Therefore, antimicrobial therapy should be guided by vitreous humour culture to assure that the causative microorganism is susceptible to the selected agent. The results of our study lead us to propose vancomycin, moxifloxacin or imipenem as first-line antimicrobial options.