Many feared that they would lose customers and revenue.
Supporters of the ban said bars and restaurants would see revenues go up.
But at Biggins' Sports Bar, owner Tracy Allen says it's been the worst summer in her 13 years of running bars.
"This summer has just been the most atrocious," she said.
Allen was worried how the indoor smoking ban would affect her business when it was put in place in June. However, she wanted to give it a chance.
"We've even put up an outdoor area that I thought was very attractive outside because you don't want it to just look like a smoker's brigade outside to take away from the outdoor appearance," she said.
The result has been a 30 percent decline in business at Biggins' and close to a 40 percent drop at her other bar...The Buffalo Bar in downtown St. Joseph.
"At the percent of decline, there's not a way we'll be able to see through six months."
Allen scoffs at those who said a whole new clientele of non-smokers would start coming in after the smoking ban took effect. She even tried to run a special.
"I said come in and show me your Smoke Free St. Joe button, your t-shirt, your banner from outside, your yard sign," she said. "We appreciate you coming in and supporting us and we'll give you a buy one, get one free sandwich. We didn't have one individual show up that evening."
Allen isn't the only one saying the smoking ban has affected business. Sharky's pool room at the Belt Sports Complex has also been seen fewer people come in since the vote on the smoking ban in April.
"It's like somebody turned the water off," said co-owner Tim Tucker. "I've talked to some of the patrons that have come in and they relayed to me that the reason some of their friends are not coming in is because of the smoking ban.
However, ten miles east of St. Joseph, outside of city limits and the reach of the smoking ban, is Easton's Pub & Grub. They're seeing a little bump in business.
"Some, not a lot," says owner Steve St. Clair. "It will probably be noticeable come wintertime. People don't realize it until they walk in the door. Then they know that they can smoke in here and it's not part of St. Joe."
The lawsuit challenging the constitutionality of the smoking ban will be in court next Tuesday.
The St. Joseph Frontier Casino is now a defendant in the suit, joining the City of St. Joseph.
The current smoking ban exempts the gaming floor of the casino.