The prison in Featherstone was the scene of a
number of rooftop protests last year
Private security firm G4S says it is tackling an "ongoing incident" at Oakwood Prison, near Wolverhampton.
It provided no further information about the incident, which a spokesman said had been "contained".
The company also said it was applying "standard procedures" to manage the problem.
The prison in Featherstone was the scene of a number of rooftop protests last year.
The G4S spokesman said: "We can confirm that there is an ongoing incident taking place on a wing at Oakwood prison.
"The situation is contained and we are applying standard procedures to manage the incident. It would be inappropriate to comment further at this stage."
The privately run prison opened in April 2012. At first it held 1,605 lower-level category C male prisoners, but it later re-categorised 256 places for category D prisoners, who are eligible for release on temporary licences.
The prison was built next to the existing HMP Featherstone and HMP Brinsford.