This paper describes a novel fault-detection technique of high voltage underground cables. Electric power systems have rapidly grown for the past fifty years. Speedy and precise fault location plays an important role in accelerating system restoration, reducing outage time, reducing great financial loss and significantly improving system reliability.  Therefore, this paper presents a fault detection, classification and fault location estimation method based on Discrete Wavelet Transform for medium voltage 11kV underground cable. Different faults (Lg, LLg, and LLLg) and at different locations 2km, 4km and 6km of 10km length are simulated by Mat Lab, and then certain selected features of the wavelet transformed signals are used as an input. From the results, it was found that the percentage error in wavelet Transform output is very less. Hence, it can be concluded that the proposed technique is able to offer high accuracy in both of the fault classification and fault location.