A 9-month-old infant had pyoderma gangrenosum (PG) and sterile osteomyelitis. Three years later the patient developed Takayasu arteritis (TA). Sterile osteomyelitis was reported in approximately 30 patients with different skin lesions, but never together with pyoderma gangrenosum. The association of PG and TA has been reported rarely, and then mainly in adults or in children over age 9 years. This rare association should alert physicians with a case of infantile PG of unknown etiology to consider the possible diagnosis of TA.