Middle ear infections are common, especially among young children, usually causing earache and some temporary (occasionally permanent) hearing loss. Zinc is an essential micronutrient, which has a role in the optimal functioning of the immune system and resistance to infection. Some people, especially children in low- and middle-income countries, may not have adequate zinc intake from food alone. Researchers have therefore examined the potential role of zinc supplements in preventing infective illnesses, including middle ear infections. The review authors searched the medical literature for studies which compared middle ear infections in people randomly selected to receive zinc supplements or not receive supplements. Ten eligible studies were found, all conducted among young children. The results of the studies provided no convincing evidence that zinc supplements reduce the occurrence of middle ear infections in healthy children. However, in one small study of severely malnourished children, those receiving zinc supplements had fewer middle ear infections.