Patrick J. Welch investigates the concentration of total deposits among banking organizations in 176 Eighth District local commercial banking markets and describes the distribution of observed levels of concentration according to a recently published Department of Justice criterion. He focuses on the extent to which concentration is due to total demand in local commercial banking markets, differences in state laws allowing branching and multibank holding companies, and physical space within local markets. He finds that the majority of the markets studied are highly concentrated. Higher levels of concentration were found in markets that had smaller population and that were located in states that allow limited branching. The effect of state multibank holding company laws and the physical size of a market on concentration was ambiguous.