This paper presents the development of fish length measurement system to obtain the fish length effectively without any contact to the fish. The device which are small and portable, consists of a USB camera that will be connected to a computer for image capturing. A range sensor is combined with the USB camera to detect and fix the image capturing distance. A microcontroller will be the control circuit for the range sensor and LED indication light will be used to allocate the device at the right distance from the fish that it measures. Image processing software, Halcon will be used to analyze and calibrate the fish image for length measurement. Mathematical equations or algorithms are introduced in the image processing software to obtain the actual fish length from the image. The actual fish length from the calculation will be illustrated in the image processing software itself. The experimental results confirms the effectiveness of the proposed system.