Very diverse assessment procedures are utilized by neurofeedback practitioners, many of which are not based on careful examination of raw EEG data followed by scientifically objective quantitative EEG (QEEG) database comparisons. Research is reviewed demonstrating the great heterogeneity in the EEG patterns associated with various diagnoses and symptoms. The fact that most patients qualify for dual diagnoses, with co-morbid psychiatric and medical conditions present, complicates the ability of clinicians to estimate what electrophysiological patterns may be associated with symptoms. In such cases treatment planning is characterized by a great deal of guesswork and experimentation. Peer reviewed publications have documented that neurofeedback treatment can sometimes be associated with both transient side effects as well as more serious negative effects. It is believed that the lack of comprehensive and objective assessment of brain functioning may increase the risk of neurofeedback either being ineffective or causing iatrogenic harm. QEEG provides reliable, non-invasive, objective, culture-free and relatively low cost evaluation of brain functioning, permitting individualization of treatment and added liability protection.