Objective: To compare visual acuity, optic disc appearance, and transient pattern reversal visual evoked potentials as markers of possible visual dysfunction in children with syndromic craniosynostosis. Methods: Serial visual acuity, optic disc appearance, and pattern reversal visual evoked potential data were recorded in 8 patients with syndromic craniosynostosis before and after cranial vault expansion. The pattern reversal visual evoked potentials were analyzed using linear regression modeling, applied to the N80 to P100 amplitude. Results: Serial optic disc appearances were available for all 8 patients and visual acuities for 7 patients. The visual acuity deteriorated in only 1 patient, improved in 4, and fluctuated in 2, before surgery. Of the 8 patients, 3 showed no papilledema in either eye at any time, 3 showed progressive bilateral swelling before surgery, and 2 exhibited only unilateral disc swelling. In all 8 patients, there was a trend for the N80 to P100 amplitude to decrease before surgery and to increase, in all but 2 patients, after surgery. Conclusions: This study suggests that neither optic disc appearance nor visual acuity assessment alone is a reliable marker of potential visual dysfunction in children with syndromic craniosynostosis. It also suggests that the pattern reversal visual evoked potential can provide early evidence of visual dysfunction before vault expansion surgery in these children; this dysfunction may recover postoperatively. Objective: To compare visual acuity, optic disc appearance, and transient pattern reversal visual evoked potentials as markers of possible visual dysfunction in children with syndromic craniosynostosis. Methods: Serial visual acuity, optic disc appearance, and pattern reversal visual evoked potential data were recorded in 8 patients with syndromic craniosynostosis before and after cranial vault expansion. The pattern reversal visual evoked potentials were analyzed using linear regression modeling, applied to the N80 to P100 amplitude. Patients. The visual acuity deteriorated in only 1 patient, improved in 4, and fluctuated in 2, before surgery. Of the 8 patients, 3 showed no papilledema in either eye at any time, 3 showed progressive bilateral swelling before surgery, and 2 exhibited only unilateral disc swelling. In all 8 patients, there was a trend for the N80 to P100 amplitude to decre ase before surgery and to increase, in all but 2 patients, after surgery. Conclusions: This study suggests that neither optic disc appearance nor visual acuity assessment alone is a reliable marker of potential visual dysfunction in children with syndromic craniosynostosis. It also suggests that the pattern reversal visual evoked potential can provide early evidence of visual dysfunction before vault expansion surgery in these children; this dysfunction may recover postoperatively.