The study of 494 Finnish children showed that inhaling second-hand smoke can lead to the thickening of arteries and their poor functioning in children.
Researchers also found a link between tobacco smoke exposure and higher levels of low-density lipoprotein (LDL) - a biological marker for "bad" cholesterol.
There was significant evidence that children inhaling tobacco smoke from the age of eight were already affected by the age of 13.
Dr Katariina Kallio, from the University of Turku in Finland, who led the study, said: "Even a little exposure to tobacco smoke may be harmful for blood vessels. We need to provide children a smoke-free environment."
Using ultrasound, the scientists found that the walls of carotid arteries, which carry blood to the brain, were 7% thicker among those most exposed to "passive smoking".
Scientists also noted that the wall of the aorta, through which the heart pumps blood to the rest of the body, was 8% thicker in such children, the study published in the journal Circulation: Cardiovascular Quality and Outcomes said.