Growth and development disorders in humans caused by zinc (Zn) deficiency have been investigated for a long time. Although marginal Zn deficiency is a common nutritional problem around the world, especially in the children of developing countries where diets have less Zn available, it is difficult to identify. This review provides the progression of studies in the effect of Zn deficiency on human growth and development, and also explains the possible mechanisms of how Zn promotes these phenomena. These mechanisms involve the effects of Zn on DNA synthesis, RNA synthesis, and cell division. The concept of zn-finger proteins explains the role of Zn in gene expression and endocrine function. Findings indicate that Zn deficiency can result in delayed growth and development which can be corrected in part by Zn supplementation.