The number of complaints made against the police has increased by 70%.
The Police Complaints Commissioner for Scotland handled 533 individual complaints for the year ending March 2011, up from 314 in 2009-10.
The figures appear in its annual review, which also revealed a 48% increase in the number of people contacting the commissioner to find out how to lodge a complaint against the police, with almost 600 enquiries.
The commissioner found that 290 complaints, 54% of the total reviewed over the year, had been handled reasonably by the police, down from 66% in 2009-10.
Strathclyde Police, Scotland's largest force, was the subject of the largest number of complaints, on 182, up from 124 the previous year. The total for the force represents around one-third of all complaints made.
Of the other seven forces, only Grampian Police recorded fewer complaints than the year before, a total of 13 compared with 45 in 2009-10.
Professor John McNeill, Police Complaints Commissioner for Scotland, said: "The increased number of complaints coming to my office demonstrates the continuing need for a dedicated independent police oversight body that the public can turn to when they believe the police have got it wrong in the way they have handled a complaint."
The report is the second annual review published by the commissioner, who was appointed by Justice Secretary Kenny MacAskill in 2009.
The commissioner is expected to scrutinise the way police handle complaints and reform the complaints-handling process.