We report a case of a male newborn delivered by vacuum at 40 weeks of gestation, who presented perinatal asphyxia, neonatal seizures and ventricular posthemorrhagic dilatation. The newborn was treated with Acetazolamide for 45 days until the reduction of the ventricular dilatation. This case shows the efficacy and the absence of collateral effects of Acetazolamide. This therapy suggests that it may be used as an alternative or an adjunct to lumbar punctures. The pharmacol treatment in the posthemorrhagic ventricular dilatation has not been well studied and there are a few related cases in the literature.