A review of 100 patients who underwent penetrating keratoplasty revealed 47 who required therapeutic soft contact lenses in the early postoperative period. Twelve corneal ulcer-infiltrates, 11 of which were culture positive, occurred during soft contact lens wear (23% incidence of this complication in contact lens fitted eyes). The most common offending organism was coagulase-negative staphylococcus. The only statistically significant risk factor for infection if a lens was used was the presence of a persistent epithelial defect (p = 0.03). Factors which could not be statistically correlated with corneal ulcer-infiltrate included keratoconjunctivitis sicca, the type of contact lens, the method of donor cornea preservation, lens hygiene, antibiotic and steroid usage, the presence of blepharitis, preoperative bacterial keratitis, and the history of a previously failed penetrating keratoplasty.