One hundred and twenty-one children were studied in this prospective, randomized double-blind, placebo-controlled comparison of the effectiveness of anticholinergic prophylaxis for the prevention of emetic symptoms following strabismus surgery. The children were allocated to three groups, to receive placebo (n = 40), glycopyrrolate (n = 40) or atropine (n = 41). The incidence of intraoperative oculocardiac reflex (OCR) and of postoperative emetic symptoms for 24 h was recorded. The incidence of OCR was 55% in the placebo group compared with 5% and 2% in the glycopyrrolate and atropine groups respectively (P < 0.05). Thirty percent (12/40) of patients in the placebo group, 25% (10/40) in the glycopyrrolate group, and 22% (9/41) in the atropine group experienced nausea and/or vomiting (difference not significant). It is concluded that prophylactic administration of anticholinergic agents during strabismus surgery in children despite being effective against the occurrence of the oculocardiac reflex, does not reduce the incidence of emetic symptoms.