Carbon monoxide (CO) is a gaseous signaling molecule that has the potential as a therapeutic agent. However, direct inhalation of CO has the risk of CO poisoning, and CO-releasing molecules (CORMs) have attracted great attention for its safe and convenient delivery. Unfortunately, major obstacle that blocks its use in medical application is its extremely short CO-releasing time. To address this issue, nanostructured scaffolds have been incorporated, and among them, peptide hydrogels have received great attention for its biocompatibility, biodegradability, and effective delivery of the gas to the target sites regardless of the surface condition. In this research, quercetin-derived, CO-releasing flavone is used instead of transition metal complexes, which inevitably leave undesired metal-containing byproducts and malevolent effects, and is conjugated to a peptide to produce a CO-releasing peptide hydrogel with improved CO-releasing properties.