In recent years, concern about the physical environment and its management has grown rapidly. This is reflected in the increasing attention given to the planning process. The growth and expansion of urban agglomerations represent a typical aggregation of some of man's activities having a marked environmental impact, such as air pollution, noise pollution, etc. Perhaps most vital among the different aspects of impact remains the water pollution. Urban hydrology studies portions of the hydrologic cycle, as modified by the presence of urban environments. Urbanization accounts for an increase in the total amount of runoff due to the increase of imperviousness of the drainage basins, thus aggravating the situation in flood‐prone areas. Equally important, the quality of the runoff waters is a concern, and more specifically its pollution effect on the receiving bodies of water, rivers, lakes, and groundwater recharge. The important recent research effort on the various aspects of these problems can be traced in the large specialized literature. This review summarizes the major works that have contributed to the state‐of‐the‐art. An important feature in urban runoff processes is the interrelationship between physical processes and man‐made structures and systems. The proposed discussion follows this classification rather than any historical sequence in three major sections as follows: physical models, simulation models, and problem areas — research needs. In the first section, the more important among the quantity and quality models of the corresponding physical processes are presented and the assumptions made in their development critically reviewed. Such physical models are interchangeably used for simulating the performance of storm‐drainage systems. The most popular among these models simulating the performance of man‐made systems are reviewed in the second section. Finally the potential problem areas and research needs for both physical and simulation models are summarized in a third section.