Italian troops are being sent to an open field hospital in Libya, the first time the country's troops will enter the country since colonial forces were ejected in 1947.
The San Marco amphibious troop carrier left La Spezia port on Wednesday with troops as part of Operation Hippocrates, a humanitarian mission.
Italy has agreed to help the Libyan government in setting up a field hospital in Misrata to care for some 2,000 soldiers wounded in its battle with Islamic State (Isis) in nearby Sirte.
Libya, with UK and US military support, has managed to destabilise IS (Daesh) in their former stronghold.
However, the national unity government set up by the UN is now facing collapse.
The hospital will feature a surgical ward and 50 beds, and will be run by 65 military doctors and medical personnel.
There will also be some 135 administrate and logistics staff and 100 soldiers from the parachute regiment.
Italy has a history of providing humanitarian aid to the country and has previously provided medicines and evacuated several dozen pro-government fighters for medical treatment at a military hospital in Rome.
Paolo Gentiloni, Italy's foreign minister, told a parliamentary foreign affairs and defence commission that it was a case of "meds on the ground" rather than boots on the ground.
He said: "We're sending a hospital, not an aircraft carrier."
However, the region remains highly volatile.
Last month, Italian charity Emergency withdrew its staff from a hospital in Gernada, eastern Libya, after suffering sustained attacks.
Italy will make efforts to help stabilise the war-torn country, both as a solution to the migrant crisis and to protect its interest in the Italian energy company ENI, which supplies 60% of Libya's gas.
However, Erasmo Palazzotto, vice-president of the foreign affairs commission, said: "Once again we are being dragged into a conflict which will not be easy to leave and which can only bring us problems."