The distribution of kininases along microdissected nephron segments was studied. Single nephrons from collagenase treated rabbit kidney were microdissected and divided into following 9 segments: 1) glomerulus; 2) early proximal tubule; 3) middle proximal tubule; 4) late proximal tubule; 5) cortical thick ascending limb; 6) distal convoluted tubule; 7) connecting tubule; 8) cortical collecting tubule; 9) medullary collecting tubule. Kininase activities in these nephron segments were measured with or without kininase II inhibitor. Kininase II and other peptidases were mainly localized in glomeruli and whole part of the proximal tubules.