We interpret the findings of the present study and other studies reported here to indicate that alterations of renal outer to inner cortical blood flow distribution develop in the early postburn period. These alterations are similar to those observed by other investigators in animals subjected to various other traumatic events. Such flow redistributions were observed in both untreated animals and those receiving intravenous fluid resuscitation. Sharp reductions in urinary chloride and sodium concentrations observed in conjunction with these blood flow shifts may be a reflection of the relatively greater perfusion of juxtamedullary nephrons, which are alleged to have greater salt-retaining characteristics than their outer cortical counterparts.