OKT3, a murine monoclonal antibody, is a potent, specific immunosuppressive agent used in solid-organ transplantation both as an adjunct during induction therapy and for treatment of steroid-resistant graft rejection. Minor, self-limiting ocular complications are often seen with this drug, of which conjunctivitis is the most common, occurring in approximately three-quarters of patients. We describe the more serious and previously unreported complication of diffuse anterior scleritis, which developed on the fifth day of OKT3 therapy in a 47-year-old man who had undergone cadaveric renal transplantation. Despite continuation of OKT3 treatment the scleritis resolved rapidly with increased dosages of prednisone.