This investigation aimed at estimation of the influence of low-intensive laser irradiation on ultrastructural changes in renal tissue according to electronic microscopy data in case of experimental renal colic. The experiment was made on twenty rabbits with a single or recurrent colic. Ten animals after a single colic were exposed to low intensive laser therapy. Electronic microscopy showed that single renal colic is associated with marked ultrastructural changes in the proximal tubules. In recurrent colic the edema and destruction were more expressed in all nephron parts. Low intensive laser irradiation suppresses pathological processes in nephrocytes both after a single renal colic and after a recurrent renal colic; has a systemic effect on the body; stimulates compensatory processes in the contralateral kidney.