Emergency services are at Twickenham station due to a person on the track.
South West Trains said a customer "had an accident" and services have been delayed as a result.
Crowds of fans heading home from the opening game of the Rugby World Cup have been pictured waiting at the station.
South West Trains said in a statement: "A customer has had an accident at Twickenham station. Services are being delayed through Twickenham while emergency services attend."
Around 82,000 people including Prince Harry and the Duke and Duchess of Cambridge attended the first game of the tournament on Friday at Twickenham stadium, to see hosts England beat Fiji.
After a temporary closure to deal with the incident the train station is open again, South West trains said, apologising for the delay.