Dibutyl phthalate (DBP) is a commonly used plasticizer in a variety of consumer products, e.g. food packaging, toys, dietary supplements, and medicinal products. DBP is a known endocrine disruptor; however, its mechanism(s) of toxicity is/use still not well understood. To investigate this further the effects of DBP, at physiologically relevant exposure levels, on regulation of expression of steroid receptor genes (Esr1, Esr2, Ar, Lhcgr), and testosterone responsive genes involved in chromatin remodeling during spermatogenesis (Uba1, Ube2d4, Hdac6, Cdyl, Brdt, Hdac1, Piwil1, Mbd2, Rhox5, Hist3h2a, H2bl, H3t) was analyzed in a rat testicular cell line (Leydig cell line LC-540). LC-540 cells were cultured for 24 h and then exposed to DBP at 5 ng/mL and 20 µg/mL for 72 h. Cell lysate was prepared and gene expression levels analyzed using NanoString Technologies nCounter® Gene Expression Assay technology. Of the genes analyzed those that were differentially regulated when the cells were exposed to DBP were all down regulated. Down regulation of expression of the genes for histone deacetylases HDAC 1 and HDAC6 was shown for the first time in a DBP-exposed testicular cell line. Expression of the gene for AR was down regulated, as was the gene for the AR-dependent reproductive transcription factor Rhox5. Also, the expression of genes for H2bl, H3t, Uba1 and Mbd2 was downregulated. DBP mediated downregulation of genes previously shown to be involved in maintaining chromatin structure during spermatogenesis, coupled with down regulation of expression of the Ar gene and an AR-dependent reproductive transcription factor gene (Rhox5) that is known to be modulated by histone acetylation, suggests that one of the mechanism of DBP-induced endocrine disruption in the male may be via epigenetic modification of testis cell chromatin acetylation.