Eosinophilic peritonitis is frequently observed in patients of all ages started on peritoneal dialysis. Peritoneal effluent may or may not become noticeably turbid, and if an aliquot for white cell count is sampled at all, eosinophils will be seen to predominate. It does not usually cause concern and settles spontaneously, many times even without the clinician noticing. Occasionally, this condition lingers on for months, and a short course of intraperitoneal hydrocortisone has been shown to be effective in clearing up the eosinophilia. We report a patient with steroid-resistant eosinophilic peritonitis and its successful resolution with ketotifen.