Epileptic activity in the adult brain not only affects preexisting neural structures but also leads to a marked increase in the number of newly generated neurons in the dentate gyrus (DG). A substantial portion of seizure-generated granule cells shows abnormal features, such as ectopic localization in the hilus or extension of aberrant basal dendrites, which may eventually lead to lasting changes of DG connectivity. Whether seizure-associated alterations of hippocampal neurogenesis represent an attempt of the injured brain to repair itself, or whether aberrant newborn granule cells interfere with proper hippocampal function and are thus part of the epileptic disease process, is still poorly understood. In this article, we will review the recent advances in understanding of the cellular and molecular mechanisms of seizure-induced neurogenesis, and will discuss the eventual impact of seizure-generated aberrant granule cells on epileptogenesis and hippocampal function.