This study describes the differences between several quantifiable variables that characterize interictal sharp EEG transients (SETS) recorded from neurologically ill neonates with proven electrographic seizures and a comparison group of apparently neurologically well babies with no known seizures. The abundance (number of sharp EEG transients per ten minutes), waveform morphology, repetitive behavior, and spatial distribution of SETS provide interpretive guidelines that help discriminate between these two patient populations.