A 69-year-old man had been intermittently experiencing abdominal pain from his 30s and was diagnosed with colonic diverticulitis. He further experienced right lower abdominal pain and received treatment. However, his condition did not improve, and he was referred to the National Defense Medical College Hospital. His abdominal pain episodes continued even after treatment for few weeks;subsequently, familial Mediterranean fever (FMF) was suspected based on the clinical course because of elevated inflammatory responses, although his body temperature was ≤38°C. After administrating colchicine as a diagnostic treatment, the repeated abdominal pain disappeared. Considering the other findings and genetic examination that showed the representative gene mutation of MEFV (M694I), he was diagnosed with FMF. This case indicates that high body temperature, one of the primary diagnostic criteria of FMF, is sometimes not evident in elderly patients, thereby causing potential misdiagnosis in some elderly patients with FMF.