Some schools in Scotland were last inspected ten years ago or more, according to an investigation.
A sample survey of over 500 primary and secondary schools in five local authorities - Glasgow, Falkirk, Highland, Moray and Shetland - revealed variations .
Figures from Times Education Scotland show 15 per cent of primaries, 67 out of 436, had not had an inspection report for a decade or longer.
Whiteinch primary in Glasgow and Staffin primary in Highland had reports dating back to 2004.
Three secondaries had not been inspected for a decade - St Paul’s High in Glasgow, Mallaig High and Dingwall Academy in Highland.
Keir Bloomer, educationalist and education convener at the Royal Society of Edinburgh, is calling for the inspectorate’s role to be reviewed.
Overall, inspections have dropped by more than 50 per cent from 362 in 2008-09 to 161 in 2016-17.
Last year, only 19 secondaries were inspected, while in 2009-09 61 underwent inspection.
But Education Scotland said it was the responsibility of local authority’s and schools to maintain standards between inspection visits at Scotland’s 2034 primary schools and 359 secondaries.
Liz Smith, MSP, Conservative shadow education secretary, described inspection gaps as “a serious concern.”
“In some cases pupils could go right through their school career without any inspection taking place. I’m sure parents will find that unacceptable.”
Seamus Searson, general secretary of the Scottish Secondary Teachers’ Association, said school inspections were not a requirement and inspection resources should be better targeted.
“Schools are checked by local authorities on a regular basis and school improvement officers pick up problems before inspectors.
“We would rather the inspectorate inspected the councils because if local authorities are doing their jobs they can identify issues and the inspectorate would only need to do a quick visit.
“It’s only schools needing support from the inspectorate which need inspections.”
An Education Scotland spokeswoman, said schools were inspected on “a proportionate basis and not on a cyclical basis.”
“The Scottish new standards and evaluation framework as specified within the National Improvement Framework and Improvement Plan will set expectations on the focus and frequency of school inspection carried out by Education Scotland in future.”