OBJECTIVE Neonatal seizures continue to present a diagnostic and therapeutic challenge to paediatricians worldwide, and are a worrying sign for both parents and clinicians alike. The present review summarizes recent evidence regarding the diagnosis, aetiology and treatment of neonatal seizures. It is timely because there is new evidence that seizures are damaging to the neonatal brain, and because prolonged electroencephalographic recordings during treatment have provided information that challenges established treatment regimens. RESULTS Neonatal seizures can permanently disrupt neuronal development, induce synaptic reorganization, alter plasticity and "prime" the brain to increased damage from seizures later in life. Phenobarbitone remains the mainstay of treatment and is effective in about one-third of cases; babies who respond tend to have a smaller seizure burden and a relatively normal background electroencephalogram. Their prognosis is better than in those who require second-line treatments. Phenytoin and lignocaine (membrane stabilizing drugs) are probably more effective than any of the benzodiazepines as second line, but very few evaluation studies have been reported. Babies who require second-line treatments are more likely to have hypoxic ischaemic encephalopathy, an abnormal background electroencephalogram and a large seizure burden, and have a worse prognosis than do those who respond to a single agent; most have significant disability at follow up. CONCLUSIONS The search for an effective antiepileptic regimen in the newborn must continue. Whether better control of neonatal seizures leads to a reduction in neurodisability in childhood cannot be determined until more effective treatments are found. Meanwhile, electroencephalography remains the most useful investigation for diagnosis and prognosis.