There are currently 1.85 million foreign minors living in Italy, up from 503,000 in 2005, the multicultural research institute ISMU revealed in its 21st annual report.
A significant proportion arrived unaccompanied on asylum boats; 2014 saw 13,026 such arrivals, while there have been 10,820 since the start of 2015.
According to ISMU, the majority of unaccompanied minors came from Egypt, Eritrea and Somalia.
The institute's president, Mariella Enoc, called the issue of unaccompanied foreign minors "a theme that we speak about very little and reluctantly", and spoke about a European project led by the Milan-based charitable Cariplo Foundation, which aims to support young people who arrive without a parent or guardian.
Earlier this year, The Local spoke to Virginia Giugno, chief of staff at Pozzallo's local authority who became the legal guardian of more than 800 children who arrived by boat, unaccompanied, in the Sicilian port town.
She had the task of finding accommodation for the children, either in reception centres or homes provided by the church or local families.
However, many of the minors who arrived alone have 'gone missing', causing problems for authorities trying to keep track of and protect them.
According to figures from Italy's Foreign Ministry in May, 4,840 children had disappeared from reception centers across the country since last summer. The government has set up a unit to deal with the cases of missing migrant children, with the aim of preventing them falling into criminal hands.
It is thought that many of the children leave with the hope of meeting up with friends or family already in Europe, but the charity Save the Children has said that those missing are vulnerable to “manual labour, domestic work, drug smuggling and prostitution".
ISMU's report also revealed that there are 5.8 million foreigners living in Italy in total, representing 9.5 percent of the population.
This figure includes both illegal immigrants and those who have gone through official channels. Italy houses a disproportionate number of migrants compared to other countries in the European Union; 14.5 percent of foreigners in the EU live in Italy, while the country's total population only accounts for 12 percent of that of the EU.
Many foreign arrivals are officially becoming Italians. Between 2013 and 2014, 231,000 foreigners were granted Italian citizenship (130,000 in 2014 alone, compared to less than 60,000 in 2012), with the biggest rise among children under 15 years old.
A more worrying statistic was the increasing number of migrants reaching Italy by boat.
In 2014 these arrivals reached the record number of 170,000, compared to only 43,000 in 2013. However, in 2015, the number has fallen slightly to 143,000, due to the danger of the waters separating Italy and Libya.
But despite the winter weather and higher risks, large numbers of migrants are continuing to make the perilous journey by boat to Italy.
On Thursday, almost 2,000 migrants were rescued off the Libyan coast in 11 different operations. The UN's children's agency has warned that women and children now account for more than half of migrants and refugees on the move, an increase from just 27 percent a few months ago.