Abstract: A method and arrangement for determining a suitable treatment frequency and/or intensity of a treatment signal used in electrical treatment. In the method, a stimulating electrical signal is directed to an object to produce different reaction types in the object at different intensities of the stimulating electrical signal. For at least three different reaction types, the intensity of the stimulating electrical signal at which a reaction type occurred is stored. The electrical signal intensities stored for the different reaction types at least at three different frequencies are compared with reference values and the frequency and/or signal intensity at which the signal intensity deviates sufficiently from one or more reference values is determined. The method utilizes the frequency and/or signal intensity found in the process in determining the suitable treatment frequency and/or signal intensity.