The man set off from Isola dei Porri, a tiny island off southern Sicily, in the early afternoon when the conditions of the sea were ideal for kitesurfing.
While out at sea, there was an unexpected change in the weather, meaning there was not enough wind for the sail to work, and the waves had risen to 1.5 meters high making it difficult for him to return to the beach, the coastguard said.
The coastguard were alerted by a friend of the kitesurfer who had noticed he had not returned from his excursion.
The coastguard immediately sent out a search and rescue boat and a helicopter, who were searching for five hours until the surfer was found in a weakened state at 10.15 p.m. (2115GMT).
The man had been at risk of being shipwrecked, the coastguard said, and was in difficulty when they found him, clinging on to the surfboard, very tired and in a slight state of hypothermia.