Broadband dielectric spectroscopy (BDS) is a method of characterizing matter from the perspective of its dielectric parameters, which varies depending on the frequency of the applied electromagnetic field. During recent years, along with its many uses, there has been an increase in interest in the use of the method in biomedical fields, especially for the characterization of normal and tumor cells. In this context, this review aims to address in the first part the theoretical bases and mathematical models that explain the principle of operation of the broadband spectroscope. Subsequently, the advantages and limitations of the method are detailed, including the difficulties that the researcher may encounter in the case of working with living cells. Finally, the most important scientific results obtained on normal and pathological cell cultures are presented, possible future research directions being suggested.