Familial Mediterranean fever (FMF) is an inflammatory disorder that is leading cause of secondary amyloidosis (AA). This study was designed to investigate the level of mean platelet volume (MPV) in AA. Seventy-four FMF, 29 AA patients and 180 healthy controls, were included. There was no significant difference between the cases in terms of sex and age. MPV levels were measured in all groups. In the FMF group, MPV level was significantly higher when compared to the control group. MPV level was significantly lower in AA group in comparison with the FMF and healthy control groups. In summary, our present study showed low MPV values in AA due to FMF.