School managers reacted angrily to Mr McCreevy's failure to provide any money towards school supervision - the issue at the heart of the secondary teachers' pay campaign.
School managers had asked the Departments of Finance and Education to set aside about £6.5 million for a new supervision scheme. This would have enabled schools to bring in trained people to supervise pupils in the absence of teachers.
There had been indications over the last month from education sources that Mr McCreevy would provide the money, but the education section of the Budget makes no mention of it.
The Association of Secondary Teachers, Ireland (ASTI) has withdrawn the service on six days so far as part of its pay campaign, and school managers have been forced to cancel classes as a result.
Their representative organisation, the Joint Managerial Body (JMB), said it was "very disappointed" that no funding was made available.
"The resourcing of schools is already very poor and now Mr McCreevy has failed to recognise a real need," said the JMB general secretary, Mr George O'Callaghan.
"This was the year to do it, but schools will just have to rely on voluntary service yet again," he added. He would be taking the issue up with the secretary-general of the Department as soon as possible.
"It is clear from this response that Government officials have little or no concept of the difficulties of managing a school and particularly of matters related to the safety of pupils," he added.
A spokeswoman for ASTI said the union would not be making a detailed comment because the Budget made no specific provision for teachers.
"Nothing in this Budget changes our position," said the spokeswoman. The union meets on Saturday to plan its next move.
The other second-level teachers' union, the Teachers' Union of Ireland, will meet tonight to decided its next move. It recently voted by a large majority in favour of taking industrial action.
Also included in the Budget is £250,000 to create the next generation of entrepreneurs. The money will be used to teach students in transition year about "enterprise culture".
Budding scientists will also get a forum to show their excellence, with Mr McCreevy providing £250,000 for a science olympiad as part of a campaign to promote science in schools.
Mr McCreevy also set aside £5 million towards helping children remain in school, although there are no details on how exactly the money will be spent.