In plants, hydrogen peroxide (H 2 O 2) acts as a signalling molecule that facilitates various biochemical and physiological processes. H 2 O 2 is a versatile molecule, involved in several cellular processes both under stress and stress-free conditions. In regulating plant metabolism under stress conditions, exogenous application of H 2 O 2 also plays a pivotal role which is manifested in improved growth, photosynthetic capacity, and antioxidant protection. Abiotic stress is an inevitable environmental factor that extensively affects and reduces growth, quality, yield, and productivity of plants. Several signalling pathways involved in H 2 O 2-mediated stress and defense responses have been extensively studied and there is ample scope of additional research that could further clarify the mechanism and modulating factors which regulate these pathways. An attempt has been made to dissect the role of H 2 O 2 under low temperature stress and how it affects plant growth and development, photosynthetic capacity, regulation of antioxidant system, and signalling.