A critical protection requirement for grid connected distributed generators (DG) is anti-islanding protection. In this paper, a new islanding detection method for any possible network loading is proposed based on utilizing and combining various system parameter indices. In order to secure the detection of islanding, eight intentional disturbances are imposed to the system under study in which two sets of them simulate the islanding condition. The proposed technique uses the adaptive notch filters for extracting the frequency of oscillation of generator’s output waveform as one of the output parameter indices. An advantage of this technique is that it does not necessitates varying the islanding detection boundaries under various system loading conditions.