Currently, a high-precision tracking control system is required for a large-capacity optical disc drive system. This paper proposes a new full field-programmable gate array (FPGA) tracking control system based on an error-based communication disturbance observer (ECDOB) considering the time delay of an optical disc drive system. The FPGA control system may have a large influence on both the integer time delay and the non-integer time delay of the control system. In order to consider the time delay, this study reconstructs the feedback control system by using the limited pole placement method. Moreover, this paper proposes a new ECDOB. The experimental and numerical simulation results confirm that the tracking performance of the proposed system is better than that of a conventional feedback control system. In full FPGA tracking control of optical disc systems, the proposed ECDOB-based tracking controller exhibits good performance.