Across the western and northern European range of diadromous Salmo salar (Atlantic salmon) during the Middle Ages (ca.500–ca.1500 CE), this fish was a highly prized object of elite human consumption, of intense seasonal fishing, of human competition, and, by the 1200s, a victim of evident depletion. What, then, enabled long traditional riverine fisheries in Scotland to become a major export producer in late medieval centuries? Provisional survey of published written records, some archival collections, and archaeological evidence establishes the great value Scottish kings and landowners placed on salmon fishing sites and their product. Knowledgeable workers for the holders of fishing rights caught salmon especially with beach seines and fixed weirs. Their catch went to elite households and urban markets for domestic consumption and was especially from the late 1300s packed in barrels for export to regions around the North Sea where diminished native runs failed to meet rising demand. Medieval Scots competed for the right to catch their salmon but did not complain that those catches were shrinking. From about 1200 royal judgments and by the early 1300s parliamentary legislation placed Scottish salmon fisheries under public regulation, prohibiting fishing at certain times and seasons and requiring all gear to permit passage of pre-migrant juveniles. Early imposition in Scotland of these limits to private fishing rights as well as an agrarian regime that (unintentionally) minimized barriers to migrants and preserved headwater spawning habitats may help explain the apparently greater sustainability of salmon stocks in Scotland than elsewhere in late medieval Europe.