Sussex Police, the coastguard, the fire service and the ambulance service were all called to Brighton Palace Pier in the early hours of this morning to rescue the man.
East Sussex Fire and Rescue Service received a call from police at 3.30am this morning to assist their rescue operation. They sent one engine to the scene to provide lighting and access.
A coastguard spokesman said they were called out at 4.30am and sent the Shoreham and Newhaven coastguard rescue teams and the Brighton inshore lifeboat to assist, as the man was reportedly in the sea.
The man was rescued by lifeboat and was left with paramedics and the police, the spokesman said.
They added that the man had been classified as 'vulnerable' by crews on the scene and said: "We hope he is getting the help he needs."
The fire crew left the scene at 5.15am, and the coastguard teams were stood down at 6.30am.