Drainages are important features of semiarid landscapes because they are areas where surface water, groundwater, and terrestrial and aquatic ecosystems converge. Management of these critical ecohydrological systems requires a sound understanding of surface water-groundwater interactions. At the basin- to landscape-scale, drainage density, location, and channel characteristics are formed upon a geomorphic and geologic template that limit where and how surface water-groundwater interactions occur. At smaller scales, semiarid surface water-groundwater interactions exhibit a high degree of temporal and spatial variability that links directly to biogeochemical characteristics and ecosystem dynamics. In this paper, we review key features of interactions in semiarid drainages, and supplement the discussion with new examples from the American southwest. We conclude by presenting a series of alternative conceptual models that describe surface water-groundwater interactions within semiarid drainages and highlight areas for future research. Copyright © 2006 John Wiley & Sons, Ltd. Published in Hydrological Processes, volume 20, issue 15, on pages 3371 - 3394, in 2006.