"The skin is the largest organ of the body and plays an important role in protecting it against various hazards such as environmental, physical, chemical, and biological hazards. An increase in oxidants beyond the antioxidant capacity of its defense system causes oxidative stress and chronic inflammation in the body. We discussed how molecular hydrogen exhibits a therapeutic effect against skin diseases via its effects on oxidative stress. Furthermore, findings from this summary review indicate that molecular hydrogen might be an effective treatment modality for the prevention and treatment of skin-related illnesses."