Ochronosis (alkaptonuria) is an autosomal recessive inherited metabolic disease that causes pigmentation by accumulation of homogenous acid in the connective tissue. The most important causes of morbidity are ochronotic arthropathy and cardiovascular involvement seen in fourth and sixth decades, respectively. In this case report, we report the prevalence of F-FDG PET/BT findings in a 48-year-old man with ochronosis who underwent F-FDG PET/BT imaging for the evaluation of mediastinal lymphadenopathy.