The use of magnesium for prevention of cerebral palsy in preterm infants has been a pressing clinical question for some time. This issue was recently brought to the forefront again after the completion of a large trial conducted by the Maternal-Fetal Medicine Units Network and published by Rouse et al in August, 2008 in the New England Journal of Medicine. After review of the complex body of literature on this topic, and the recent addition of this important piece of evidence, we discussed the "pros" and "cons" of the evidence-based use of magnesium for prevention of cerebral palsy at the annual meeting for the Society of Maternal-Fetal Medicine as a luncheon roundtable. The evidence currently available does not make the clinical decision of whether or not to use magnesium for the prevention of cerebral palsy as clear as we would hope. It appears that despite well-designed and executed studies on this critically important topic in obstetrics, the answer to the question of whether evidence-based medicine supports the use of magnesium for neuroprophylaxis in preterm infants remains unclear.