The objective of this study was to determine the transcriptional regulation of Npr1 gene (coding for guanylyl cyclase/natriuretic peptide receptor-A; NPRA) by the vasoactive hormone angiotensin II (Ang II). NPRA synthesizes the intracellular second messenger cGMP in response to ANP binding. The studies on the effect of Ang II on the promoter activity and expression of Npr1 gene were carried out in cultured mouse mesangial cells. The cells were cultured in Dulbeccos modified Eagles medium (DMEM) containing 10% fetal bovine serum, and transiently transfected using Lipofectamine-2000 reagent. Hormone treatments were carried out in serum-free DMEM containing 0.1% bovine serum albumin. Promoter analysis of Npr1 gene showed that the region approximately −1182 bp to −916 bp upstream of transcription start site contains cis-elements involved in Ang II-mediated transcriptional repression. The data showed that Ang II-mediated transcriptional repression of Npr1 gene is mediated through AT1 receptor subtype. The luciferase assay data from protein kinase inhibitors clearly suggested that the repression is mediated by both protein kinase C (PKC) and tyrosine kinase pathways. The PKC in particular has an additive effect on the Ang II mediated transcriptional repression and expression. The findings of this study will be critical in understanding the role of ANG-II and PKC in the transcriptional regulation of Npr1 gene and the pathophysiology of hypertension and homeostasis.