Perimeter intrusion detection systems are an integral part of most physical security systems. Perimeter fencing is widely used to isolate and protect public and private places such as airports, military bases, power stations and security related applications. Fence structures merely prevent a percentage of intrusions or postpone them. A higher level of security needed to monitor and investigate activities on or around the university. Perimeter Intrusion Detection System (PID) focusing on the fence intrusions. The system used major components as Arduino board, 8x8 LED display, ultrasonic sensor, 16x2 LCD display module and speaker. The unauthorized person who tries to intrude the university would be sensed, detected and alarm would generate a signal that an intruder was trying to enter the university. The sound level depended on the distance, the nearer the intruder and stronger would be the alarm signal. PID system displayed the distance of the object or personal found in its region on the LCD display. This system was very useful for security applications. Ultrasonic sensor would be searching if there was a motion in its range.