Couch potatoes were warned that their lifestyle also increased the risk of death from other causes including cancer.
Individuals who spent hours watching television greatly heightened the chances of dying early from heart attacks and strokes, they found.
Compared with those watching less than two hours of TV, people who sat in front of the box for over four hours a day were 80 percent more likely to die for reasons linked to heart disease.
Researchers in Australia monitored 8,800 adults for six years to see what impact watching TV had on their long-term health.
They found that each hour spent per day in front of the television increased the risk of death from all causes by 11 percent. It also raised the risk of dying from cancer by 9 percent and the risk of heart disease-related death by 18 percent.
The scientists warned that it was not only telly addicts whose lazy lifestyles put them in danger. Any prolonged sedentary behavior, such as sitting at an office desk or in front of a computer, posed similar risks, they said.
It also made no difference whether or not a person was overweight or obese.
The average amount of TV people watch each day is three hours in both Australia and the UK, said the scientists.
