In recent years much progress has been made in the field of neurochemical monitoring for the acutelly injured brain. The development of safe continuous microdialysis techniques coupled with microanalytical methodology can generate semi-continuous time profiles of the changes in numerous brain analytes such as lactate, glucose, pyruvate, excitatory amino acids, structural amino acids, indicators of free radical generation, cytokines, adenosine, and neuroprotective drugs. Descriptive studies have shown profound, prolonged, and severe abnormalities in many of the analytes measured and the next phase is to determine the effects of therapeutic interventions upon these parameters. This field of research has contributed tremendously to our understanding of pathomechanisms in acute human brain damage.