PURPOSE: To define the clinical outcome and microbiological pattern of bacterial endophthalmitis that were referred at the Jules Gonin Eye Hospital from January 1997 to September 1999. METHODS: Patients were recorded in a computerised databank and were managed according to a standard protocol. An anterior chamber tap combined with a vitreous biopsy by the pars plana was performed in all patients. The treatment included an intravitreal injection of 1 mg Vancomycin and 400 micrograms Amikacin diluted in 0.2 ml NaCl 0.9%. Postoperatively hourly therapy Cefazolin 50 mg/ml and Garamycin 9 mg/ml was applied. To determine possible risks factors a standard form was sent to all referring surgeons. The following data were analysed: delay of onset, risk factors, initial and final visual acuity. RESULTS: From January 1997 to September 1999, 31 patients were referred. 18/31 (58%) of the cases were admitted between April and June of each years. The mean age was of 75 +/- 10 years. Initial visual acuity ranged from light perception to 20/40. 17/31 of the patient's cultures were positive. The major pathogen were Staphylococcus epidermidis in 9/31 patients and Staphylococcus aureus in 4/31 patients. No correlation between the endophthalmitis and the surgical technique or perioperative management of the patient, could be determined. Visual outcome was significantly improved in 56.7% of the patients. CONCLUSIONS: The severity of outcome could be correlated to the type of bacteria isolated. The high prevalence of panophthalmitis from March to June suggests that a climatic factors may be involved in its pathogenesis.