Purpose.To assess the utility of donor corneoscleral rim cultures.Methods.A retrospective review of the culture results of 774 corneoscleral rims that remained after trephination of corneas for transplantation into patients at our academic medical center between January 1992 and November 1997.Results.Forty-one (5.3%) corneoscleral rim cultures yielded microorganisms, mostly coagulase-negative staphylococci. Two patients developed endophthalmitis (one withStaphylococcus aureusand one withPseudomonas aeruginosa) within 3 months after transplantation; each had a negative corneoscleral rim culture and neither patient's infection was temporally related to the transplant procedure.Conclusions.Preoperative donor corneoscleral rim cultures are unreliable predictors of endophthalmitis complicating corneal transplantation and, therefore, are not useful in the clinical management of patients having corneal transplants. Moreover, the discrepancy between the results of corneoscleral rim cultures and subsequent endophthalmitis renders them invalid as a quality assurance procedure. Instead, for patients with suspected endophthalmitis after corneal transplantation, we recommend that corneal surgeons select antimicrobial therapy based on current guidelines and the results of directed sampling. Furthermore, eye banks should prospectively track recipients who develop clinical endophthalmitis, immediately notify the corneal surgeon who transplanted the matched cornea of that used for the index case, and, in selected situations, attempt to identify a possible source of contamination.