In this study, we discovered that NSD2 specifically interacts with the DNA-binding domain of androgen receptor (AR) via its HMG domain, and the nuclear translocation of both NSD2 and AR is enhanced in the presence of ligand. Furthermore, we also demonstrated that the over expression of NSD2, but not of NSD2 (DeltaSET) HMT-activity defective mutant, enhanced the mRNA level of PSA in a dose-dependent manner. A chromatin immunoprecipitation assay showed that NSD2 protein is recruited to the enhancer region of the PSA gene by AR in an agonist-enhanced manner. Taken together, these results uncover a potential role for NSD2 in AR-mediated transcription, implicating NSD2 in prostate carcinogenesis.