Albumin concentration were measured in blood serum (As) and in peritoneal exudate (Ae) of patients with peritonitis and acute pancreatitis. As and Ae registration during several days revealed strong negative correlation between an index, Ae\As, and serum albumin As in 51% of the patients. The absolute value of the linear correlation coefficient, r, exceeds 0.7 in each of these patients. Moreover, pooled data in this group of patients showed that integral correlation coefficient was very high, r ≈-0,94 at p<0.01. In other words, the higher ratio Albumin in exudate\Albumin in serum, the lower Albumin is in serum. Other patience had either lesser coefficient of the negative correlation, between –0.3 and –0.7 (14% of all patience) or very low negative or even positive correlation of the index, Ae\As, and serum concentration As (35% of all patience). Probable albumin redistribution between blood, peritoneal exudate and tissue pool in relation to ratio exudate Albumin\serum Albumin is discussed.