A hundred and four cases of post cataract endophthalmitis with positive vitreous cultures are discussed. Functional results depend largely on the infecting agent but even after Staphylococcus epidermidis infections some eyes may be lost. Although post lens surgery endophthalmitis carries the best prognosis in the endophthalmitis group, 40% of the eyes are lost, sometimes caused by a delayed vitrectomy decision. Comparing intracapsular and extracapsular lens surgery two big differences were noted: (1) the bacteriology, and (2) the functional results. The bacteriological spectrum of the ICCE was composed of 1/3 of S. epidermidis, 70% of Gram + cocci and 80% of Gram+organisms. After extracapsular lens extraction the majority of cases (60%) were caused by S. epidermidis (statistical significance 0.01). The difference in functional result is explained by the difference in bacteriology: if only the S. epidermidis cases are compared, functional results between both categories are nearly equal. ECCE seems to make the eye more vulnerable to infection by a low virulent agent.