The crew from the nearby station responded to a mayday call just before 10:00am after being alerted a man had gone overboard from a vessel off Burntisland.
The drama also led to a helicopter being scrambled as emergency services raced to the scene.
The man was brought back on board, and was able to walk off the boat to a waiting ambulance.
A spokesman for the RNLI crew said: “The man was pulled on board a nearby workboat as the lifeboat came in alongside.
“But with the nature of the incident we continued with casualty care on board the vessel whilst he was brought in to Burntisland Harbour.
“A cross agency effort between Scottish Ambulance Service, Kinghorn Coastguard, South Queensferry Coastguard and Rescue Helicopter 199 ensured he was taken safely ashore and to further hospital care.
“He is expected to make a full recovery.”
It was the KInghorn crew’s fourth call out of the week - prompting a plea to the public to take care when on the water during the heatwave.
They were called out three times in one day, including two shouts to twice to Cramond Island, and one to Portobello.
The crew which attended the Burntisland incident was Scott McIlravie, Neil Chalmers and Paul Stather, with Ralph Johnston, Kim Chapman, Donnie Maclean, Mike Chalmers and Paul Wibberley providing tractor/shore help.