Detention before trial has been one of the most neglected areas in the whole administration of criminal justice. In the past, attention has been focussed almost exclusively on detention after trial (i.e. sentencing), which touches the lives of significantly fewer persons than detention before trial. There has been no previous examination in Canada of the utility or effectiveness of its operation. This study will fill an important need by documenting statistically the extent and nature of custody before trial in the Toronto Magistrates’ Courts, where the overwhelming majority of citizens charged with criminal offences in the Toronto area are tried. Although the study is primarily directed at practices before trial in Toronto, many of these practices can be found in other cities throughout North America.Specific areas of importance which were investigated here include the use of the summons; the extent to which accused persons are detained in custody both before and after the first court appearance; bail-setting practices and the ability to raise bail; the activities of professional bondsmen; the enforcement of penalties for absconding; and the relationship between custody and the outcome of the trial. Much of the presentation of the data is descriptive, but attempts are made throughout the study to prove statistically the existence of casual relationships. The result is a work which brings together in lucid and scholarly form important evidence which will be valuable to lawyers and all who are professionally concerned with social problems, and of interest to everyone with a regard for the administration of justice.