Safety operation/measures are of great concern and among them islanding phenomena takes an important role for reliable energy. Therefore, the utility grid requires anti-islanding protection for a safe and reliable operation. For this purpose, a different and fast method is proposed for islanding detection in PV systems. The suggested method is based on instantaneous power calculation at the point of common coupling and able to detect islanding condition within a few sampling interval. No further calculation is needed to detect islanding problem for grid connected PV systems.