Adult-onset Still’s disease (AOSD) is a rare systemic inflammatory disorder of unknown etiology. We report a 22-year-old female patient, admitted to our department with fever, rash, large joint pains, and mild proximal weakness of both upper and lower limbs. With further evaluation of the patient and exclusion of infections, hematological malignancies, and connective tissue disorders, AOSD diagnosis was established with strikingly elevated serum ferritin level. This patient is the daughter of a patient who was diagnosed as having dermatomyositis in our department 2 years earlier. The mother was re-evaluated, and AOSD could not be excluded through the normal serum ferritin level.