Jean Doublin, owner of Ruthie's, filed the lawsuit in June seeking to stop the ban and citing Missouri law that allows taverns to make nonsmoking areas unavailable indoors as long as signage is posted outside the bar to that effect.
Signs saying "Non-smoking Areas are Unavailable" appear on every door at Ruthie's, The Springfield News-Leader reported Thursday.
However, Greene County Judge Jason Brown upheld the ordinance.
Doublin said she has lost close to 75 percent of her business since the ban went into effect.
But anti-smoking advocates were quick to praise the ruling.
"I think it's a continued victory for public health, which is what we view this ordinance to be," Stephen Hall, communications director for the American Heart Association in Springfield, said.