Of the about 2.36 lakh children who went missing in the last three years, 1,61,800 have been traced, Minister of State for Parliamentary Affairs Paban Singh Ghatowar said during the Question Hour.
"Unfortunately about 75,000 are still untraced," he said.
The Centre, he said, has issued advisories to states to appoint nodal officers at all police stations to deal with such cases and make registration of FIRs mandatory. The advisories followed two interim orders of Supreme Court in January 2013, he said.
The Supreme Court had ordered mandatory recording of FIR with regard to missing children and formation of special Juvenile Police units in different states.
Mr Ghatowar, who was replying on behalf of Women and Child Development Minister Krishna Tirath, admitted that the issue of missing children has assumed an "alarming" proportion.
He informed the House that a web portal 'TrackChild' has been launched on a pilot basis to deal with the issue.
States are also being asked to update data on missing children on the portal, he said.
The Minister further said the problem of children going missing was due to economic and social reasons and also due to criminal activities.
He, however, said there was no information that missing children were being sold in neighbouring countries.
When asked about children being kidnapped from hospitals, he said there have been such cases but law and order is a state subject.
As per a data of National Crime Records Bureau (NCRB), 34,406 children were untraced in 2011, 23,236 in 2010 and 18,166 in the previous year.