Fifty-two healthy male Swiss albino rats, aged three months, were used in this study. They were divided into four groups: control (C), diabetic (D), cadmium (Cd) and diabetic + Cd (D + Cd). Diabetes was induced in the D and D + Cd groups by administration of alloxane (5 mg/100 g). After this treatment, the Cd and D + Cd groups were injected with CdCl2 i.p. (2 mg/kg/week). At the end of the two month experimental period, EEGs of the four groups were recorded and amplitude spectral analysis was computed by Fast Fourier Transform (FFT) algorithm. Significant amplitude (dB) increment was observed in 16-30 Hz of Cd group compared with C and D groups. Significant amplitude decrement was found in the 2-4 Hz frequency band of the D + Cd group compared with C, Cd and D groups.