OBJECTIVE: To determine whether the clinical features of neonatal seizures are of value in predicting outcome. STUDY DESIGN: Demographic features, clinical seizure types, etiologic factors, and laboratory findings of all 77 patients with seizures admitted to our neonatal intensive care unit over a consecutive 7-year period were extracted from the medical records. RESULTS: Twenty-three (30\%) died; 59\% of the survivors had abnormal neurologic examinations, 40\% were mentally retarded, 43\% had cerebral palsy, and 21\% were epileptic at mean follow-up of 3.5 years. Compared with patients with other seizure types, those with subtle and generalized tonic seizures had a significantly higher prevalence of epilepsy (P =.04 and P =.01 respectively); mental retardation (P =.02; P =.007), and cerebral palsy (P =.03; P =.002). Subtle seizures were, in addition, more likely to be associated with abnormalities on the neurologic examination at follow-up (P =.03). Similar outcome comparisons for those with focal and multifocal clonic, focal tonic, and multifocal myoclonic seizures revealed no significant differences. However, patients with >or=2 seizure types were significantly more likely to have epilepsy (P =.02), mental retardation (P =.001), cerebral palsy (P =.001), and abnormal examinations (P =.05). CONCLUSIONS: Clinical semiology is predictive of outcome in neonates with seizures and suggests the presence of unique pathophysiologic processes for different seizure types.