The Care Inspectorate is looking into a number of complaints made about the Aberdeen Waldorf School Kindergarten.
The investigation comes after another nursery in the city, Hamilton School nursery, was last month closed down and two women charged by police.
A Care Inspectorate spokesman said: “We have received complaints around staffing and the care of children at the Aberdeen Waldorf SchoolKindergarten.
“We are currently investigating these issues and the outcome of our investigation will be published in due course.
“Because concerns have been raised about the school as well as the nursery, we are also carrying out a focussed joint inspection with colleagues from Education Scotland over the next few days.”
There is no police involvement in the investigation, the Care Inspectorate said.
An Education Scotland spokeswoman added: “Education Scotland has today commenced an inspection together with the Care Inspectorate of Aberdeen Waldorf School. Once the inspection is complete a parental letter detailing the findings will be published on our website.”