This report is based on an examination of both evaluation reports and interviews with many of the participants, supervisory personnel, and trial judges in whose courts the participants appeared. An Interchange of Counsel Program (ICP) similar to that conducted in Hennepin County (Minneapolis) improves the professionalism of attorneys prosecuting and defending criminal cases and is valuable as a training and career retention program. To be successful, an ICP must have the complete support of the prosecuting atttorney and the public defender. This support may be weakened if either is an elective office, because of the fear that the electorate may not understand the value of the program. An ICP, to avoid conflict-of-interest problems, should involve offices of sufficient size so that knowledge of pending cases cannot reasonably be imputed to members who move from the prosecution to defense, or vice versa; further, such offices should adopt and follow strict policies with respect to case assignments and conduct of participants similar to the policies adopted and followed in Hennepin County. For example, a program should involve participants who volunteer, who are career motivated, have approximately 2 years of experience, and are determined by their parent office to be the suitable for the program. Restrictive laws and ethical rulings in a number of jurisdictions may make it infeasible to conduct an interchange program. Appended materials include a summary of ICP conference proceedings, applicability of the conflict of interest laws, and ethical considerations. (Author abstract modified).