The purpose of this study was to investigate the expression of human beta-defensins (hBD-1, -2) in dental pulps by reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. The mRNA transcripts of human beta-defensin-1 and human beta-defensin-2 could be detected by performing RT-PCR. With immunohistochemical staining of pulp tissue using antisera to hBD-1 and -2 it was possible to demonstrate cytoplasmic expression in odontoblasts. The results demonstrate that not only oral keratinocytes at the epithelial surface but also odontoblasts express human beta-defensins. Thus odontoblasts take part in the innate immune system and human beta-defensins may play an important role in the innate host defense of human dental pulp.