Matrix metalloproteinase-9 (MMP-9) causes adverse remodeling, whereas hydrogen sulfide (H₂S) rescues organs in vascular diseases. The involvement of MMP-9 and H₂S in diabetic renovascular remodeling is, however not well characterized. We determined whether MMP-9 regulates H₂S generation, and also whether H₂S modulates connexins through N-methyl-D-aspartate receptor (NMDA-R) mediated pathway in the diabetic kidney. Wild type (WT, C57BL/6J), diabetic (Akita, C57BL/6J-Ins2^Akita), MMP -9-/- (M9KO), double knockout of Akita/MMP-9-/- (DKO) mice and in vitro cell culture were used in our study. Hyperglycemic Akita mice exhibited increased level of MMP-9 and decreased production of H₂S. H₂S synthesizing enzymes, cystathionine β-synthase (CBS) and cystathionine -lyase (CSE) were also diminished. In addition, increased expressions of NMDA-R1, connexins-40 & -43 were observed in diabetic kidney. As expected, MMP-9 mRNA was not detected in M9KO kidneys. However, very thin protein expression and activity was detected. No other changes were noticed in M9KO kidney. In DKO mice all the above molecules showed a trend towards baseline despite hyperglycemia. In vitro, glomerular endothelial cells treated with high glucose showed induction of MMP-9, attenuated H₂S production, NMDA-R1 induction and dysregulated conexins-40 & -43 expressions. Silencing MMP-9 by siRNA or inhibition of NMDA-R1 by MK801 or H₂S treatment preserved connexins-40 & -43. We conclude that in diabetic renovascular remodeling MMP-9 plays a major role and that H₂S has therapeutic potential to prevent adverse diabetic renal remodeling.