On the basis of the average annual salary of correctional officers at $12,000, the annual cost of each officer perimeter post is calculated to be $55,200 dollars. Electronic perimeter security has been proposed as one means of reducing the cost of perimeter security. The 1979 survey of State correctional agencies, the Federal Bureau of Prisons, and the military services, to which 46 States and the Federal Bureau of Prisons replied, ascertained that only 11 of the 60 users of electronic perimeter security systems installed them specifically as a means of reducing manpower. Twelve installed them to correct breakdowns in security, and 23 used them to increase security without reference to manpower. The six system types represented in the survey were (1) ground sensor systems (17 reported), which use buried liquid-filled hoses to indicate ground intrusions of security; (2) fence disturbance sensors (13 reported), which are designed to respond to fence vibration; (3) infrared (6 reported), which is a 'line-of-sight' system consisting of infrared transmitters and photo detectors; (4) taut wire systems (7 reported), which involve a wire between fence posts attached to micro switches at the posts; (5) microwave sensors (6 reported), which involve a transmitter and receiver separated by a 'line-of-sight' distance; and (6) electric field sensors (5 reported), which involve 2 or more wires paralleling the perimeter fence, 1 of which is energized by an alternating current setting up a magnetic field around the other wires. An important finding from the use of an effectiveness scale comparison was that users of the least expensive system were just as satisfied as users of the most expensive systems. Many users reported enough savings in manpower to pay for the system in under 2 years. More use of electronic security to reduce manpower appears feasible, assuming proper selection, installation, and maintenance. Tabular data on the cost and effectiveness of the systems are provided.