Periosteal chondroma is a rare, benign tumor of hyaline cartilage. Periosteal chondroma is commonly found in the metaphysis of long bones or the small, tubular bones of the hands and feet. Periosteal chondroma arising in the rib is an extremely rare event. Described is the case of a 55-year-old patient with periosteal chondroma of the rib found after more than 3 years of thoracic pain.