Bars and restaurants say they have lost up to a quarter of their takings since the law came into force in 2007.
Now politicians are voting on a plan to allow smoking in places where food is served, if under 21s are barred from entry.
In Las Vegas, where just about anything goes, smoking is still allowed inside bars, shops and casinos.
Bryn Nicholas, 31, is on holiday in Las Vegas from the UK.
“You don’t even really smell the smoke. It’s all air conditioned,” he said.
In Vegas, people often light up whilst gambling and enjoying a drink, but many believe the laws should be relaxed further.
Venues had to adapt to the new rules in 2007 and some complain it has cost them business.
“We had to put up walls with closing doors,” said David Barnes, manager of Ellis Island casino, bar and restaurant.
“I just believe that it hurts the restaurant and bar business overall.”
But he says changing the law again would do more harm than good.
“Those who want to smoke can still step outside, they just can’t do it at the table… smokers would have to wait longer to get a table,” he said.
Vegas is Nevada’s most populated city and attracts millions of visitors each year.
Some agree that the rules should be relaxed, but many say they should stay as they are.
Josh Martinez, 23, and Sophia Alvarez, 22, are on holiday from southern California.
“Everybody’s here to do what they want,” Josh said.
“So people smoke, sure, whatever. I haven’t had any problems with it.”
But they disagree with the plans to allow smoking in restaurants.
“I hate the smoke, you should be able to keep that separate from everybody else,” added Sophia.
In April, the Nevada state senate voted in favour of relaxing the smoking ban.
The bill now faces one more vote in the state assembly before it becomes law.
If passed, the change would make Nevada the first of 24 US states where smoking is banned in bars and restaurants to relax the law.
So far, no others have shown signs of softening state-wide laws, but some cities have acted alone to relax anti-smoking laws.