OBJECTIVE This study performed 99mTc-MAG3 renal scintigraphy on rabbit kidneys and evaluated its ability to identify obstructive or non-obstructive kidneys. METHODS Renal function was assessed during a four-week post-obstruction period by obtaining planar images of 99mTc-MAG3 activity following an ear vein injection. The individual renal function was evaluated by renal scintigraphy in conjunction with histopathological and morphological examinations. RESULTS The renal perfusion of 99mTc-MAG3 in the right kidney with a ureteral obstruction decreased with time. The width, height, and cortical thickness of the obstructed right kidney were significantly larger than those of the left kidney. A histopathological examination four weeks after the ureteral obstruction revealed a typical pattern of urinary tract obstruction, including multiple tubules, enlargement of the interstitial area, and cytoplasmic vacuoles. CONCLUSIONS 99mTc-MAG3 renal scintigraphy provides the kidney shape and size and can identify potential obstructive and non-obstructive kidneys in rabbits.