Since their first description in 1875, Merkel cells have remained an elusive cell type. Their origin as well as their classification as mechanoreceptors have been a matter of controversy and intense discussion. The peptidergic granules in these cells are suggestive of neuroendocrine functions, but their discovery has raised additional questions regarding Merkel cell function. Essential aspects of structure, development and function of normal Merkel cells and Merkel cell carcinoma are presented in short chapters, providing concise and up-to date information on this fascinating cell type.