This retrospective case control study was conducted in the Genetic Diagnostic Centre in Turkey. It examined the prevalence of keratoconus in two groups; patients with Familial Mediterranean Fever (FMF) and age matched controls free of FMF, who were tested for other genetic disorders in the same time period and living in the same regions. Four patients out of 100 with FMF were identified to have keratoconus, whereas no patients in a control sample of 300 had keratoconus. This difference was statistically significant. The 4% keratoconus prevalence in the FMF group was also statistically higher than the highest keratoconus prevalence reported in the literature. Patients who have FMF with a homozygous mutation of the Familial Mediterranean Fever (MEFV) gene seem to be most at risk of having keratoconus. The authors report the newly found association of keratoconus and FMF, linking both diseases to defects in MEFV gene. This results in exaggerated pro-inflammatory actions of interleukin 1B and might be an important factor in the development of keratoconus in patients with FMF. Further studies are warranted to confirm the genetic basis for this newly found association.