Seizures represent an important clinical manifestation of inborn errors of metabolism. The presence of myoclonic seizures and very early onset are clues to a metabolic disorder. Specific correlations between age of seizure onset and electroencephalogram patterns with inborn errors of metabolism are discussed. The explosion of information in neurogenetics and metabolism mandates increasing awareness of appropriate metabolic diagnostic and therapeutic strategies in the setting of certain epilepsies. Specific laboratory, imaging, and treatment considerations are included to present updated material in a field that continues to expand rapidly.