The term computerized EEG refers to the recording of the brain activity obtained by a computer-based system. In order to evaluate the frequency and types of abnormality of quantitative EEG in resting state, we planned this cross sectional case control study. Seventeen patients with major depression and 21 healthy controls were included to study. Structured Clinical Interview for DSM III-R (SCID), Beck Depression Inventory and computerized EEG recording were obtained from 19 scalp point with 12 channel montage. Fast Fourier transform and frequency analysis of major EEG bands were compared with healthy controls. Additionally, general distribution patterns, hemispheral asymmetries, and regional differences of each wave forms were determined. All of the patients had normal EEG findings with visual analysis. As a result of quantitative analysis 53 % of patients had abnormal EEG findingsw ith an increasement of delta and theta waves and decreasement of alpha waves especially in frontotemporal regions of nondominant hemisphere. We concluded that diagnosis of depression, sensitivity of visual EEG could be supported by such methods as quantitative analysis and spectral analysis. However, more extensive studies must corroborate our results for sufficient interpretetion of data derived from quantitative analysis.