FIELD : medicine.SUBSTANCE : invention relates to medicine and is a method for determining mitochondrial dysfunction in patients with non-alcoholic fatty liver disease (NAFLD), which consists of a clinical and laboratory research, characterized in that DNA is isolated from leukocytes of the venous blood of a patient with NAFLD, followed by a polymerase chain reaction using standard primer pairs, followed by determination of length of end sections of peripheral blood leukocyte chromosomes, and at the obtained values of this indicator above, the reference ones determine mitochondrial dysfunctions in patients with NAFLD, in particular, for hepatology and clinical laboratory diagnostics.EFFECT : proposed invention allows to improve the accuracy, sensitivity and specificity of the method for determining mitochondrial dysfunction in patients with non-alcoholic fatty liver disease (NAFLD), to reduce the time for its implementation.1 cl, 1 tbl, 2 ex