The incident occurred on Tuesday at around 11 am local time.
"The Iuda Naofa, a 23m Irish fishing vessel, was taking on water 48 miles north of the Butt of Lewis. A coastguard rescue helicopter was requested to attend the scene and drop a salvage pump onto the Iuda Naofa to pump off the ingress of water,” a spokesman for the MCA said.
Still, the water flooded the boat and it started to sink. Two of the crew were airlifted onto the nearby sister vessel, the Star of Hope. The other three suffered mild hypothermia and were transferred by helicopter to the Western Isles Hospital for treatment.
Paul Tunstall,coastguard duty watch manager said the weather conditions on scene had been very bad with force 6 winds and heavy seas.
“Evacuating the five crew swiftly and safely before the vessel went down was a great achievement,” he added.
Video: Iuda naofa rescue 20012015