Lincolnshire Fire and Rescue crews will be conducting routine training exercises at HMP Lincoln throughout Thursday, June 29.
Fake smoke will be used during the exercises and fire engines will be used to simulate a major incident.
Crews are warning residents not to be alarmed if they see emergency services and smoke at the prison.
Lee Marsh, Station Manager at Lincolnshire Fire and Rescue, said: “We are running a routine fire training exercise at HMP Lincoln today.
“You may see a number of fire engines around the prison which will be taking part in the exercise.
“Some fake smoke will be used to make the exercise seem as realistic as possible, so please don’t be alarmed if you see smoke coming from the prison buildings.
“We wanted to let local people know before the exercise begins to prevent people from worrying that something catastrophic has happened.
“I’d also like to remind people to only dial 999 if there is a genuine emergency.
“These training exercises are vital to ensure that the emergency services are ready and prepared, should a major incident happen at the Prison.”