Nowadays, milk adulteration and, in particular, milk fat adulteration represents a big problem. Because of its high price, ghee and butter has always been the object of adulteration by adding less expensive vegetable oils or animal fat. The determination of fatty acids by gas chromatography (GC) followed by calculation of suitable ratios is commonly used to detect extraneous vegetable oils or animal fats, but with the introduction of some lipids sources in cow's and buffalo's diets, the detection of extraneous fat become difficult. The dielectric properties (Breakdown voltage (KV) test) of oils are electrochemical and thermo-physical property widely used to determine the shelf life of mineral oils used in transformers. This property was determined in some vegetable oils, some animal fats, milk fats and margarine oil to see whether there is a big variation between them easy to be used to distinguish between these oils and fats or not. Also, this property was determined in mixture of milk fat with different edible oils and animal fat in different ratios. The obtained results indicated that it could be possible to depend on the dielectric breakdown voltage as a rapid and easy method to detect milk fat adulteration with other vegetable oils and animal fats.