The Department of Education has said that 98% of Leaving Certificate students have registered for the calculated grades student portal.
In a statement, the department said that 59,859 out of 61,029 have registered so far.
The deadline for the remaining students to register has been extended from 10pm tonight until midday tomorrow.
Secondary schools around the country have been helping to facilitate registration and anyone having difficulties is advised to contact the department's support team.
Earlier, Minister for Education Joe McHugh said if there are students who had not signed up by 10pm, the department would contact their school and see the reasons behind it.
He said he did not want to "leave anybody outside the system", in particular those who may have had difficulty or encountered unforeseen circumstances.