There are relatively few differences between the Japanese and American versions of arcade Final Fight. This would not be the case for certain console ports, however...

Japanese	American
The Japanese version states the exact year when the game takes place: 1989, which happens to be the same year the game was made. The American version changed this to a vague "sometime in the 1990's..." instead. The date Final Fight takes place was later retconned to 1987.

Japanese	American
During the intro, when Haggar turns on his TV, Jessica briefly appears. After a few seconds Damnd will then appear. For the American version, Jessica never appears on the screen, only Damnd does.

Japanese	American
The special credits sequence has brief comments from the development staff in the Japanese version. These were not translated for the American version, instead, the text just states the staff's nicknames. The layout for the mugshots was also altered.

Japanese

These messages, from the game's development staff, are only in the Japanese version.