The Dental Practice, based in Cheltenham, has been using a crocodile logo since the mid-1990s but only ran into trouble when it tried to register the logo in 2004.
It was then that Lacoste's lawyers said that it feared The Dental Practice logo could be confused with the famous Lacoste crocodile and that the confusion could harm its business.
According to reports, The Dental Practice's dentists represented themselves at the first hearing over the case, which was held in May 2007 at the Intellectual Property Office in Newport. The judge found in favour of the dentists that time, but Lacoste appealed the case.
That appeal has also now been defeated. One of the dentists who defended the practice, Dr Simon Moore, said that Lacoste's approach had been "very much using a sledgehammer to crack a nut".
Moore told The Times: "We were very surprised such a big international company would feel threatened by one town dental practice."
Lacoste has been told to pay £1,000 towards The Dental Practice's legal costs after the first hearing, and a further £450 following the appeal.