More than 35,000 court cases dating back three years have not been entered into the criminal records computer system, a report has found.
Her Majesty's Inspectorate of Constabulary (HMIC) said information in the records was often incomplete or out of date, and that this would have an impact on public safety.
They blamed a lack of direction at senior level.
Scotland's police forces say action has been taken to improve the situation.
HMIC for Scotland Bill Skelly said accurate records were "critical".
But he said that since an original inspection in 2005, progress to improve the system remained slow, with the majority of forces still lacking a "clear strategic direction".
The reliability of data on the police national computer (PNC) depends on input from the three main criminal justice agencies - the police, prosecution service and courts, according to Mr Skelly.
He said: "We found that in practice the flow of information between the three needs to be more robust if we are to prevent omissions and failures arising between the Scottish systems and the PNC.
"Moreover, as all computer record errors currently default to the police, every force in Scotland is responsible for correcting not only its own errors but those of all criminal justice partners.
"The result is an inefficient use of police time and resource simply to support the system itself."
The number of impending prosecutions also came under fire, with 188,000 in the system, compared with 385,000 across all of England and Wales.
The report said many of the cases would already have been dealt with by courts or prosecutors, but not updated, although these mainly referred to minor cases.
More serious offences, such as sex crimes, are closely scrutinised by police and prosecutors.
Mr Skelly added: "We had already drawn this matter to the attention of Acpos (the Association of Chief Police Officers Scotland) and the SPSA (Scottish Police Services Authority) and I am pleased they have now taken action to identify the main reasons behind cases not being updated and are working with criminal justice partners to rectify the situation."