Histone deacetylases 2 (HDAC2) is expressed in the central nervous system; it has multiple functions in neural plasticity. However, we do not know if HDAC2 is also involved in the pathology of epilepsy. Here we report that HDAC2 was expressed in the brain tissues of both control and temporal lobe epilepsy (TLE) patients. Results from immunofluorescence and immunohistochemistry showed that HDAC2 was primarily located in the nucleus and that TLE patients exhibit significantly more HDAC2 positive cells than control. Western blotting showed that HDAC2 protein levels were significantly higher in TLE than in control brain. Moreover, in the rat model of TLE, there was a sustained enhancement of HDAC2 expression in rat models of TLE. HDAC2 was significantly increased in both the acute (1 day) and chronic (60 days) animals compared with control group. These results suggest that HDAC2 play an important role in the pathogenesis of human TLE. Synapse, 2012. © 2011 Wiley Periodicals, Inc.