The aim of our study was to evaluate the prognostic value of serial polysomnography in the detection of developmental outcome following neonatal seizures during the first 6 months of life (presumed time of complete maturation of sleep).Our results show that serial polysomnography could detect the developmental outcome following neonatal seizures with a high degree of sensitivity. The initial polysomnogram performed shortly after the onset of seizures as well as the 3 months follow up were the most sensitive in detecting outcome as compared to the 6 months follow up. The grading system established in the study correlates the initial and follow up polysomnograms and thus allows accurate and sensitive prediction 0f outcome. Abnormal MRI was a sensitive detector of poor outcome but the reverse is not true. Clinically the etiology of seizures did not seem to influence the development of infants, on the other hand the abnormal neurologic examination performed during the acute stage proved to be a sensitive predictor of poor outcome.