Small hand-rolled cigarettes are popular
One million people a year will die from tobacco smoking in India during the 2010s, research predicts.
The New England Journal of Medicine study found smoking already accounts for 900,000 deaths a year in India.
The study warns that without action, the death toll from smoking will climb still further.
It predicts smoking could soon account for 20% of all male deaths and 5% of all female deaths between the ages of 30 and 69.
The researchers have calculated that on average, men who smoke bidi - small hand-rolled cigarettes common in India - lose about six years of life.
Men who smoke full-size cigarettes shorten their lives by about ten years.
And for women bidi smokers the figure is about eight years.
The figures are based on a survey of deaths among a sample of 1.1 million homes in all parts of India carried out by about 900 field workers.
Among men who died between the ages of 30 and 69, smoking caused about 38% of deaths from tuberculosis, 32% of deaths from cancer and 20% of deaths from vascular disease.
Lead researcher Professor Prabhat Jha, of the University of Toronto, said: "The extreme risks from smoking that we found surprised us, as smokers in India start at a later age than those in Europe or America and smoke less."
It is estimated that there are about 120 million smokers in India.
The study found that, among men, about 61% of those who smoke can expect to die at ages 30-69 compared with only 41% of otherwise similar non-smokers.
Among women, 62% of those who smoke can expect to die at ages 30-69 compared with only 38% of non-smokers.
Professor Amartya Sen, of Harvard University, said: "It is truly remarkable that one single factor, namely smoking, which is entirely preventable, accounts for nearly one in 10 of all deaths in India.
"The study brings out forcefully the need for immediate public action in this much-neglected field."
Dr Anbumani Ramadoss, India's health minister, said: "I am alarmed by the results of this study.
"The government of India is trying to take all steps to control tobacco use - in particular by informing the many poor and illiterate of smoke risks."
Jean King, director of tobacco control at Cancer Research UK, said India could learn from the UK, where falling smoking rates over the last 30 years have coincided with the world's biggest drop in deaths from lung cancer, particularly among men.