One in three Indians smokes some form of tobacco, officials say, and a study published in the New England Journal of Medicine in February this year said one in every 10 deaths in India from 2010 would be smoking-related.
The government has made smoking a top issue, with Bollywood stars urged by the health minister to stub out their cigarettes, on-screen smoking forbidden and health workers telephoning residents in the capital offering help to quit.
But the drive against smoking in public foundered.
"The problem was public spaces are a huge sphere, but there was no onus on the person in charge of the public place to implement the law," said Braj Kishore Prasad, the health official in charge of India's anti-smoking drive.
Prasad said the new ban has increased the areas included in the prohibition, roping in college campuses, bars and discos, and has directed establishments to appoint anti-smoking officers who will be liable if people smoke.
The fine amount remains the same, at 200 rupees, and people may still smoke at home, in their cars, in parks and on streets.
India's cigarette giant, the Indian Tobacco Company, and the country's hotel lobby fought for a stay but the plea was rejected by the Supreme Court Monday.
That cleared the way for the new ban to take effect on Thursday, the birthday of ascetic peace icon Mahatma Gandhi, who did not smoke, drink alcohol or eat meat.
Restaurant and bar managers said they would comply with the law.
"We are very clear on this aspect. We will not let anybody smoke," said Shahzad Rashid, who manages Mist restaurant, located in the five-star Park Hotel in the city's centre.
But he admitted it might take a toll on the hotel's popular Agni disco, which like many bars and restaurants here sells cigarettes.
"Out of 100 patrons, 90 who drink probably also smoke," he said. "People also drink more when they have a smoke."
Smokers, particularly young ones, have expressed dismay about the new ban.
Call centre workers have said they are worried they will not make it through long nights of answering international customer service calls without cigarettes.
But Indian officials said they were hopeful everyone would come around.
"A lot of awareness has been created in the country," said Prasad, who hopes to eventually broaden the ban.
"This is very, very necessary for public health."
At least some in the capital were hopeful the new law would not be the last word on smoking, though.
"Maybe there will be a change in the law after some time. They keep changing the laws, sometimes this way, sometimes that way," said Q'BA restaurant-bar manager Sunil Tickoo, who hopes the ban will be eased for venues with liquor licences.
Tickoo also wondered how tight enforcement would be this time.
"The first one or two weeks there will be a lot of checking. It will be like a red-hot pepper has burst, but after that the fire will die down," he said.
"But of course we will remain non-smoking as long as the government maintains the ban."