The Aquarius, a boat operated by charity group SOS Mediterranee along with Doctors Without Borders (MSF), brought 606 people including 241 minors to Palermo after a series of rescues at sea on Tuesday and Wednesday.
Nearly 180 of the youngsters were unaccompanied, the group said. Rescuers could be seen carrying the youngest charges off the ship, including toddlers in pyjamas and a week-old baby wrapped up tightly in a pink blanket.
"The many rescue operations carried out by Aquarius in recent days over a very wide geographical area show that the humanitarian crisis is still underway or even worsening in the central Mediterranean," SOS Mediterranee said.
Among the women pulled to safety from unseaworthy dinghies, 11 were pregnant, two in their ninth month.
The migrants, who set sail from Libya for Italy, came from countries including Benin, Eritrea, Ethiopia, Nigeria, Syria, Somalia and Yemen.
Numerous migrants told aid workers they had been victims of sexual violence and torture in conflict-hit Libya, where they were held prisoner for months.