Over 184,000 immigrants from outside the European Union became Italian citizens last year, more than triple the number in 2011, figures from Italy's national statistics agency Istat showed on Tuesday.
A total of 184,638 such people acquired Italian citizenship in 2016, compared with less than 50,000 in 2011, Istat said.
The largest group were Albanians (36,920), followed by Moroccans (35,212), while 41.2 percent of new Italian citizens were people aged under 20, according to Istat.
Among more than 541,000 people from outside the EU who gained Italian citizenship between 2012 and 2016, over 24,000 moved abroad, the Istat data.
Around 61,000 new Italian citizens were born in Italy over the period, Istat said.
Around 800,000 people would instantly become Italians under a hotly contested bill granting citizenship to children born in Italy to a foreign resident or who arrive before their 12th birthday and spend at least five years in formal education.
Italy's teachers have began a hunger strike over the long-stalled bill, which transport minister Graziano Del Rio and other politicians said they had joined last week.
The bill was approved by the lower house of parliament almost two years ago, but rightwing and centre-right parties have blocked its passage in the upper house Senate, where the government depends on support from its junior coalition partner, the centre-right Popular Area (AP) party.
Italy's regional affairs minister Enrico Costa, who is from AP, resigned in July over the bill, saying a conflict between his "role" and his "beliefs".
Immigration is one of the most controversial issues facing politicians in Italy, where over half a million foreigners have arrived in the past three years, mostly sub-Saharan Africans who landed by boat from Libya.
