Quantitative electroencephalography (QEEG) has a long history and its clinical usefulness has gradually become well known. QEEG is a noninvasive, easy, comfortable and inexpensive way to check the brain status, but it is not specific to a diagnosis and requires sufficient experience in its clinical interpretation. The techniques and parameters of QEEG are increasingly being developed and studied, so their utilization will become more widespread in the future. QEEG in addiction disorders has not been fully studied, but it has many possibilities. The symptoms of addiction disorder and QEEG characteristics in some addictions show features that are clinically beneficial to diagnosis and treatment. Various complementary studies in the future are expected to make it more useful in clinics.