A glaucomatous patient treated with echothiophate iodide subsequently became pregnant. The drug was withdrawn at 32 weeks because of unknown fetal hazards. A month before delivery a right anterior sclerotomy and peripheral irridectomy were performed under general anesthesia avoiding succinylcholine chloride, with its known aphoea risk, as muscle relaxant. The pseudocholinesterase activities of both mother and infant were assayed at intervals after delivery. The results suggest that echothiophate iodide had traversed the placental barrier and caution is indicated in its future use in such cases.