Fibroblast growth factor-2 (FGF-2) regulates several vascular endothelial cell functions, including proliferation. It has been suggested that the regulation may be modulated by reactive sulfur species (RSS), which are hydrogen sulfide and biomolecules containing persulfide/polysulfide groups. Since RSS promote vascular endothelial cell proliferation, we hypothesized that FGF-2 regulates the levels of RSS-producing enzymes in the cells. Bovine aortic endothelial cells were cultured and treated with FGF-2, and intracellular RSS levels were determined. The expression of RSS-producing enzymes, cystathionine γ-lyase (CSE), cystathionine β-synthase, 3-mercaptopyruvate sulfurtransferase, and cysteinyl-tRNA synthetase 2, was evaluated, and the intracellular signaling pathway that mediates FGF-2 regulation of RSS accumulation was investigated. We revealed that FGF-2 upregulates the expression of RSS by selectively inducing CSE via the ERK1/2 signaling pathway in vascular endothelial cells. The effect of FGF-2 on the function of vascular endothelial cells may be modulated by intracellular RSS, especially higher-molecular-mass RSS such as protein persulfide, the levels of which are increased by the growth factor.