Expert systems can be considered as one of the methods of computer design. This paper presents an intelligent expert system for the active filter design (ESAFD). Acknowledge base for the design of the four basic filters configurations is developed namely LPF, HPF, BPF and BSF (notch filter) of the n-th order depending on the stability and cost. In the case of LPF and HPF the three known methods of design namely BESSEL, BUTTERWORTH and CHEBYCHECV are considered and for the approach of the other two types of active filters the inference engine proceed by searching for the most convenient method of design, taking into consideration the highest quality factor for the type of filter in question using the Multi-feedback or State Variable approach for the case of BPF, while it uses the Twin Tee and Active Inductor for the BSF(notch filter). This system was tested for all types of filters used in various electronic circuits. PROLOG and PASCAL were used to construct the system