Eighteen suture abscesses that developed after penetrating keratoplasty in 15 patients were reviewed. The time from keratoplasty to the diagnosis of an abscess ranged from 1 to 53 months with a mean of 21.5 months. In 13 of the 18 cases, the patient was taking topical steroids at the time of diagnosis. All were culture-proven bacterial ulcers, except for one case that had a positive Gram's stain, but no growth on culture. The organisms cultured were Staphylococcus epidemidis (six eyes), Streptococcus pneumoniae (five eyes), Sta. aureus (four eyes), Str. viridans (two eyes), Klebsiella oxytoca (one eye), Serratia marcescens (one eye), Moraxella sp (one eye), and Escherichia coli (one eye). The offending suture was removed in all cases, and the eyes were treated with topical fortified antibiotics (cefazolin and tobramycin). After treatment, 67% (12 of 18 eyes) had clear grafts, 17% (three of 18 eyes) were scarred, and 16% (three of 19 eyes) had failed grafts. Intensive topical steroid therapy was used when a subsequent graft rejection developed. Retained sutures following corneal transplants can result in sight-threatening infections and should be considered for removal as soon as the wound is well healed.