According to a survey, 240,000 patients with taste disorders in Japan visited otolaryngologists in 2003. This represents an approximate 1.8-fold increase from the number of patients reported in 1990. Taste, as well as smell, responds to chemical substances ; thus they are called chemical senses. Taste dysfunction can be attributed to various causes, including direct impairments of taste-related neural pathways in the peripheral and/or central nerve and secondary impairments in association with other diseases. Among secondary impairments, taste disorders caused by zinc deficiency and drugs being taken for other diseases are common. Zinc, an essential trace element, has been examined extensively in its relation to taste disorders. In this article, we describe various causes of taste disorders with a focus on their relation to zinc. In addition, zinc therapy, which has been examined previously from a relatively objective perspective, is also discussed as a treatment for taste disorders.