An excessive accumulation of anandamide (N-archidonoylethanolamine, AEA) is associated with septic shock. Results of previous studies have suggested that mRNA coding for the AEA degrading enzyme fatty acid amide hydrolase (FAAH), which converts AEA into arachidonic acid and ethanolamine, might be down-regulated in septic shock. We used real-time reverse transcription PCR assays to measure relative FAAH mRNA concentrations in the whole blood of 30 healthy donors and eight sepsis patients to ascertain whether such down-regulation takes place. Our results suggest that concentrations of FAAH mRNA in male and female samples from healthy donors are similar, but that concentrations are significantly lower in sepsis patients. These findings indicate that mRNA expression of FAAH in human whole blood correlates with sepsis, and may bi an interesting biomarker for predicting the onset of septic shock.