This paper presents the characterization of transients resulting from faults in transformers using discrete wavelet transform. (DWT). This characterization will aid in the. development of, an automatic detection method for internal incipient faults in the transformers. The detection. method can provide information to predict failures, ahead of time so, that the necessary corrective actions ate taken to prevent outages and reduce down times. The analyzed data are obtained from simulations and experiments for different normal and abnormal ope rating cases internal short circuit faults, magnetizing such as external faults, inrush, and internal incipient faults. The simulation method and experiment setup are discussed. The experiments and simulations are conducted on a single-phase transformer as an example case. The results of applying the DWT are discussed.