Cigarette smoking is an important risk factor for renal damage due to its effects on small interlobular arteries. We investigated the effects of long-term passive smoking on renal vascular structures in healthy rats exposed to smoke soon after birth. Forty-two Sprague-Dawley rats (21 males and 21 females) exposed to passive smoking comprised the experimental group and 33 non-exposed rats (17 males and 16 females) comprised the control group. The number of renal vessels, as well as the level of glomerular capillary sclerosis, hyalinosis of arterioles, and myointimal hyperplasia of arteries was assessed in renal biopsy specimens. The mean number of renal vessels in male and female rats exposed to passive smoke (21.71 and 13.81, respectively) did not significantly differ from the mean number of renal vessels in male and female control rats (22.47 and 13.06, respectively) (p>0.05). Levels of glomerulosclerosis, hyalinosis, and myointimal hyperplasia also did not differ between the experimental and control groups (p>0.05). Histopathologic evidence of renal vascular damage was not found in young rats exposed to passive smoke for 4 months. A longer or higher degree of exposure to cigarette smoke components may be required before such changes manifest, and aging and primary renal disease may play a role.