The androgen receptor (AR) is a transcription factor that drives the differentiation of prostate epithelium by regulating the expression of several hundred genes. Conversely, AR also plays a central role in prostate cancer (PCa) development, and it continues to be active in tumors that relapse after castration (castration-resistant prostate cancer, CRPC). The transactivation function of AR has been extensively studied, and AR can also function as a transcriptional repressor on a distinct set of genes, but the identity of the AR regulated genes that are critical for PCa remain unclear. Moreover, the extent to which AR acquires new functions during PCa development and progression remains to be determined. Recent studies have highlighted the central role of chromatin structure and histone posttranslational modifications in determining the spectrum of genes regulated by AR and all other transcription factors. While the role of DNA methylation in the epigenetic regulation of gene expression is well established, it is now appreciated that chromatin structure plays a central and dynamic role in the epigenetic regulation of gene expression. The focus of this review is on AR interactions with chromatin and how they regulate AR function in PCa development and progression.