Intermittent fever has a wide variety of causes such as infectious, cancers, or inflammatory disease. Intermittent fever is sometimes a diagnostic challenge when fever appears as the first and isolated sign of the disease. Adult onset Still disease and juvenile chronic arthritis are mainly the most common cause of intermittent inflammatory fever. Some frequent diseases gives intermittent fever in few cases like ankylosing spondylitis, pulmonary embolism, sarcoidosis or Crohn's disease. Some rare inflammatory disease gives typical intermittent fever like genetic periodic fever. Other rare diseases give sometimes intermittent fever like vasculitis, polychondritis, Castleman disease, etc. Drug fever and factitious fever are other classical causes of intermittent fever. Diagnosis of inflammatory intermittent fever is frequently based on the clinical course but some biological tests and computerized tomographic scans are worthwhile tools. Follow-up of undiagnosed cases is needed.