Complaints against officers from Thames Valley Police rose by 23% last year, the Independent Police Complaints Commission (IPCC) said.
The watchdog recorded 1,167 complaints against the force in 2009/2010, compared with 947 the previous year.
Some complaints contained several allegations - the total number was 2,183, up by 15%, and most were about neglect or officers being rude or late.
The force said the report would allow it to address community concerns.
Thames Valley Police covers Berkshire, Oxfordshire and Buckinghamshire.
The IPCC published its annual complaints statistics for all 43 police forces. Nationally, complaints were up 8% on last year, at 33,854.
Deputy Chief Constable Francis Habgood said: "Thames Valley Police as a force cannot continue to improve the standard of service we provide to our communities if people do not let us know when they are unhappy.
"Police officers are regularly placed in dangerous and highly stressful situations while keeping our communities safe.
"The challenge for these officers is to maintain the high standards of professionalism and service expected by members of the public while carrying out their duties."
Graham Smith, chairman of the Thames Valley Police Federation, which represents police officers below the rank of superintendent, said: "If there's things we need to learn, then we'll learn them.
"Complaints are part of the role we carry out and we accept that.
"In any democratic society you have to have a right to complain. Also, people's perception of rudeness may vary, or an officer may have had no sleep.
"The figure has risen by 220 complaints, which is less than one a day."
Mike Franklin, IPCC commissioner for the South East, said: "Thames Valley has seen a higher than usual rise in complaints against its officers and this is something that they need to look carefully at and understand the reasons why.
"Although it may at first glance seem to be bad news for the force, I believe that part of the reason for the increase in numbers of people complaining is improved access to and confidence in the complaints system."
Thames Valley Police recently announced it would axe 270 jobs this financial year after its budget was cut by £12m.