From its littoral margin to the open ocean, the western South Atlantic (Fig. 1) is marked at all depths by circulation patterns and exchange processes that are centrally important to the regional marine resources and local economies, and to the global flux of heat and dissolved substances. Among other important characteristics, the Southwest Atlantic (SWA) is characterized by the presence of the Brazil Current (BC), a warm western boundary current that, while weaker than the Gulf Stream in terms of mass transport, is energetically comparable to its North Atlantic counterpart, particularly in the region of confluence with the northward-flowing Malvinas Current (MC) at approximately 38°S. Because of the wide range of issues needed to be understood in terms of the physical oceanography, this oceanic region has been addressed by several important scientific programs, a few of which are listed in Table 1 and indicated on Fig. 2. Results from these and other programs are summarized here and recommendations for future efforts are offered.