Around 15,000 smear tests have been delayed by two months after invitations weren’t sent out due to a technical issue.
The health service has issued an apology and promised to process the tests quickly once they take place.
NHS National Services Scotland (NSS) said an “external supplier” suffered a technical issue which stopped letters being sent out for eight days in late August.
Around 15,000 patients are now being contacted and NSS said those affected would receive letters in the coming days.
The charity Jo’s Cervical Cancer Trust said many women would be facing “additional anxiety”, but urged them not to worry.
Chief executive Robert Music said: “This incident comes when we are living in very uncertain times and for those affected we know this news may cause additional anxiety.
“It is important to know that HPV and cell changes take many years to develop into cervical cancer, not months, and the immune system will often get rid of them without the need for treatment, so please try not to worry.
“The steps being taken by NHS Scotland will hopefully ensure events such as this do not happen again and that the cervical screening programme continues to improve.”
NSS said it was working with the supplier to make sure the error doesn’t happen again and insisted delayed cervical screenings would be processed quickly.
Allan Wilson, clinical lead for the Cervical Screening Programme, said: “Additional safeguards have been put in place and we continue to closely monitor and review the situation.
“We are doing everything possible to minimise any impact on those who are affected. Participants affected by the issue who wish to have a cervical screening test will be prioritised within sample-taking locations.
“Their tests will also be processed as quickly as possible within the laboratory to ensure there is no further delay.
“We deeply regret any concern that this incident may have caused.”