This paper gives a brief review and short summary on physiological and biochemical evaluations of human mental workloads. Physiological evaluations consist of peripheral physiological evaluations and central physiological evaluations. Peripheral physiological evaluations mainly include heart rate and heart rate variability (HRV) recorded from electrocardiograms (ECGs), blood pressure, respiration, eye blinks, skin potential, and hemodynamic indices. Central physiological evaluations mainly refer to the cerebral cortex, including electroencephalograms (EEGs) and event-related potentials (ERPs). Biochemical evaluations mainly include catecholamines, cortisol, and immunoglobulin A (IgA) collected from blood, salivary, or urinary samples. They are all objective measurements to evaluate mental workloads when particular mental tasks are performed. © 2011 Wiley Periodicals, Inc.