Major histocompatibility complex class I-related chain A and B (MICA/B) function in the regulation of protective responses due to stress induced expression. One of the major causes of the morbidity is sepsis. The objective of this study was to measure the mRNA levels of these genes in the control and sepsis patient groups. Data showed increases in mRNA concentrations of MICA and MICB in the Patient Group in contrast to the Control Group. However this level was found higher than MICA mRNA concentration in the patient group. The current study is the first report according to the researchers' knowledge representing the significant increases in the MICA and MICB expressions in the sepsis. This might provide a useful data for emphasizing these molecules as sensitive biomarkers. Further research is needed to enlighten the detail mechanisms of the MICA/B roles and to develop new treatment approaches.