New figures from the Scottish Government show the proportion of children with access to a registered teacher has fallen from 75.4% in 2012 to 72.8%.
The biggest drops are in Aberdeen, East Lothian, the Western Isles, Glasgow, Inverclyde, Shetland, Stirling and West Lothian. Research has repeatedly underlined the importance of teachers to the quality of nursery education, particularly in the most deprived areas.
Councils are employing more child development officers instead, arguing they are better qualified than ever before and allow nurseries to open for longer to meet the demands of working parents.
Greg Dempster, general secretary of the Association of Headteachers and Deputes in Scotland, which represents senior primary school staff, said he was "very disappointed" by the trend.
"This appears to run counter to the Scottish Government's policy of providing meaningful and sustained access to a nursery teacher," he said.
However, Douglas Chapman, education spokesman for Cosla, said councils were committed to high standards in nursery using a "range of professionals".