The most important complication of FMF is the development of amyloidosis. It is more common in the eastern Mediterranean compared to the US. The individual response to endotoxin may have a significant effect on the development of amyloidosis in FMF patients. To investigate the association between CD14 promotor C-159T polymorphism and development of amyloidosis, one hundred and forty-six patients who had FMF and had not developed amyloidosis; 26 with FMF and secondary amyloidosis and 92 controls were genotyped at the CD14-C159T locus. There was no difference between the genotype distribution of FMF patients (CC 30.0%, CT 50.0%, TT 20.0%) and controls (CC 29.2%, CT 45.8%, TT 25%); or between FMF patients with amyloidosis (CC 30.8%, CT 53.8%, TT 15.4%) or without amyloidosis (CC 29.2%, CT 45.8%, TT 25%). Our study shows that the CD14-C159T polymorphism is not associated with FMF or development of amyloidosis in the population studied. The effect of the genetic variations in the endotoxin signaling pathway under different environmental conditions such as high and low endotoxin exposure remain to be determined.