Police discretion is essentially the exercise of a power that results in the differential treatment of offenders. Discretion may be used in the nonenforcement of a particular law, the nonrecognition of a particular violation, nonarrest of a particular suspect, and noncharge of a particular suspect. Included are the issuing of warnings rather than charges and the selection of one charge in preference to another. There is no legal authority for the police use of discretion except under the police powers of arrest in the criminal code. To examine police and public attitudes toward the use of police discretion, a survey was conducted in Ottawa, Ontario, during the latter part of December 1970 and the first week of January 1971. Two randomly selected populations were used, one consisting of 100 citizens and one composed of 100 police officers, with the latter divided equally between the Ottawa police and the Royal Canadian Mounted Police. The survey was accompanied by personal interviews and the completion of a questionnaire. Both the public and the police favor the use of police discretion. Its use in relation to charges in serious offenses was close to being evenly split for and against for both populations. Both populations realized that the use of discretion necessarily discriminates in the treatment of persons contacted by police, but this was not considered undesirable. Where discretion was used, both populations wanted the police to look beyond the evidence to the total circumstances of the case. Twenty-seven notes and further readings are provided.