Organic acid testing occupies a small but important place in medical diagnosis. Typically, it is used to aid in diagnosing metabolic disorders. It also can be used to assist in the diagnosis and management of mitochondrial dysfunction, nutrient deficiency, some infections and toxicant exposures and people with chronic illness. In addition, OAT testing can assist in identifying imbalances in gut microbiota and yeast overgrowth. OAT testing can be incorporated into patient care by evaluating treatment efficacy and metabolic changes over time. This presentation will give overview and clinical implementation to the use of OAT testing in practice