Figures from the Care Inspectorate show a 4% increase in the number of complaints - more than half of which were upheld - about childcare facilities in six months last year.
The regulator's updated dossier on failures and dangerous practices is also now revealed after the latest series of swoops.
Unannounced visits by inspectors found disturbing behaviour by untrained staff and lapses over legally required child protection checks about the criminal history of new recruits in relation to minors.
In one case, children were ignored by staff and an inspector had to prompt a worker to take care of a distressed infant.
Concerns over medication were raised at another nursery where a child was given the wrong medicine.
The regulator has now set up mentoring programmes to tackle such problems.
Facilities were inspected across the country and among those criticised were the ABC Tots Nursery in Armadale, West Lothian, the Wonderland Nursery, Arbroath, Angus and Noah's Ark Nursery in Lochgelly, Fife.
ABC Tots was described as unsatisfactory on all counts and told by the inspectors that "significant improvements must be made" after electric cables were found to be in reach of children, and infection control problems with water dispensers said to be unsafe.
A spokesman for the nursery said a new management team is in place and "feedback from parents has been very good".
After visiting Wonderland Nursery the inspectors said: "We were alarmed about the lack of information sharing and documentation in relation to child protection. The manager was advised of this at the time of the inspection and fully supported our guidance and acted on our advice.
"We also identified poor practice in relation to hand washing, nappy changing and storage of cleaning products."
Noah's Ark was also described as either weak or unsatisfactory.
The inspectors said staff needed more training and support to address "serious flaws in their practice".
Neither Wonderland or Noah's Ark responded to requests for comment.
There were 233 complaints about the day care of children between May and November last year, compared to 223 for the same period the previous year, and 56% were upheld.
Annette Bruton, chief executive of the Care Inspectorate, said: "We know that the majority of childminders and nurseries in Scotland perform well.
"We do not hesitate to act on concerns and have legal powers to force change where necessary.
"We have also successfully implemented mentoring schemes which pair poorly performing services with services that perform well."
Scottish Labour Education spokeswoman Kezia Dugdale said: "The overall trend in increasing complaints is worrying and raises serious questions about the training and qualifications of those working in the private sector. It's vital that the Care Inspectorate does follow up to ensure that these nurseries radically improve their standards."
Chief executive National Day Nurseries Association Scotland Purnima Tanuku said: "Everyone in the early years sector agrees there should be a robust inspection process to ensure children are getting the best possible care.
"What is of paramount importance is high quality childcare and what must be remembered is the Care Inspectorate reports 80-90% of the nurseries it inspects are of a high standard."