The move comes after the Educational Institute of Scotland (EIS) lost its case against Glasgow City Council earlier this year.
The EIS had gone to court seeking an order to prevent the council from appointing new headteachers, who were not registered, at 10 schools catering for three to five-year-olds.
The teachers' union also wanted the Court of Session in Edinburgh to set aside a decision that introduced a policy whereby the post could be held by individuals without any teaching qualifications.
But the local authority contested the judicial review and emerged victorious, with Lord Brodie ruling against the EIS. He said the union had failed to establish the decision was unlawful.
Now the EIS is going back to the Court of Session to appeal the decision.
The legal wrangle, which will be heard next year, cuts to the heart of the current tension between the role of a nursery school and whether its primary purpose is to educate or care for the children of working families.
Union leaders argue that removing qualified teachers from posts within the nursery sector will damage the quality of education on offer.
However, the city council believes there is no legal requirement to consult the EIS and argues that the staff who run nurseries do not need to be qualified teachers as long as there is sufficient input from teachers in what is taught.
Gerry Moynihan, QC, for the council, said that from Scottish Government guidance on pre-school teachers, it could be seen that deciding what was an adequate number of teachers in an education authority's schools was a matter for its own discretion.
He said there was no need for a teacher to be the head of the establishment and teaching provision could be met by peripatetic staff.
Larry Flanagan, general secretary of the EIS, said: "We can confirm we will proceed with our legal challenge next year, as we remain extremely concerned about the implications of the ruling for the quality of nursery education.
"We continue to believe that all education in early-years settings should be led by appropriately qualified, registered teaching staff and that heads of centres should also be qualified teachers.
"All available research evidence, both internationally and that produced closer to home by Scottish education agencies, emphasises the importance of teacher involvement to ensure a quality early-years education."
Last month, headteachers, teachers and parents attacked the Scottish Government's record on nursery education, arguing the service is being dismantled.
In recent years, councils have replaced teachers with lower-paid child development officers – previously called nursery nurses – partly on cost grounds, but also because they work longer hours.
Local authorities argue child development officers are better qualified than ever before, following the introduction of new qualifications up to degree level, and their use allows them to open nurseries for longer to meet the demands of working parents.
However, research has repeatedly underlined the importance of teachers to the quality of nursery education.
According to Europe's largest pre-school research project –carried out in England – there is a direct correlation between the quality of a pre-school setting and the qualifications of staff.