There are very few reports on hypersensitivity reactions in association with titanium-based materials so that the existence of allergy to titanium is still put in question. We report on a patient in whom impaired fracture healing and eczema localized to the perioperative area developed upon titanium-based osteosynthesis. Patch testing gave no reactions to titanium nor to nickel, chromium, or cobalt. However, in the lymphocyte transformation test, the patient's lymphocytes showed markedly enhanced proliferation in vitro to titanium. After removal of the titanium material, fracture healing was achieved and the eczema cleared. Parallel to this, in vitro hyperreactivity to titanium disappeared. Although contact allergic reactions to titanium have been very rarely reported, these findings support a diagnosis of titanium allergy in our patient.