ETS-1 plays an important role in angiogenesis and cancer invasion, and hypoxia is a common feature in these phenomena. We examined whether hypoxia influenced ETS-1 expression. Hypoxia induced ETS-1 in a human bladder cancer cell line, T24, and promoter analysis revealed that the deletion of -424 to -279 bp from the human ETS-1 promoter decreased the hypoxia-mediated inducibility. This region contained a hypoxia responsive element-like sequence, and HIF-1 bound to it under the hypoxic condition. Double-stranded synthetic oligonucleotides of this sequence as a decoy inhibited the hypoxia-mediated induciblity. These results indicate that hypoxia induces ETS-1 via the activity of HIF-1.