The development of hydrogels that are responsive to external stimuli in a well-controlled manner is important for numerous biomedical applications. Herein we reported the first example of a hydrogel responsive to hydrogen sulphide (H2S). H2S is an important gasotransmitter whose deregulation has been associated with a number of pathological conditions. Our hydrogel design is based on the functionalization of an ultrashort hydrogelating peptide sequence with an azidobenzyl moiety, which was reported to react with H2S selectively under physiological conditions. The resulting peptide was able to produce hydrogels at a concentration as low as 0.1 wt%. It could then be fully degraded in the presence of excess H2S. We envision that the novel hydrogel developed in this study may provide useful tools for biomedical research.