The Premier League fear the two recent racism rows that have rocked English football are damaging their global brand.
The league says in a message on its Twitter account that support for a team should “never include excessive aggression or discrimination toward the opposition.”
It asks fans to report “unacceptable behaviour” to stadium staff or the Kick It Out anti-discrimination group.
Manchester City forward Raheem Sterling was racially abused by Chelsea fans in front-row seats last month. Chelsea banned four men under investigation and condemned anti-Semitic chanting by fans at a Europa League game in Hungary against Vidi.
A Tottenham fan was arrested after a banana skin was thrown toward Arsenal forward Pierre-Emerick Aubameyang as he celebrated a goal.
It is understood there are concerns the incidents are having an impact on the way the Premier League is perceived around the world.
The League have done some excellent work in the past in fighting racism, yet there is an acknowledgement behind the scenes that much more has still to be done.
A spokesman said: ‘If anyone is found to have racially abused a Premier League player they deserve to be punished. We will support any action taken by the club or the authorities.’
Source: The Premier League / UK Media