Head trauma is one of the most common etiologies of olfactory dysfunction. It is difficult to use either the olfactory function test or magnetic resonance imaging to directly assess the course of damage to olfactory nerves. Thallium-201 (²⁰¹Tl) olfacto-scintigraphy has been shown to be an able means for objectively assessing the olfactory nerve transport function. It is expected to be used to evaluate olfactory nerve regeneration after damage to the olfactory nerves. However, no such result has been reported. We present a patient who lost his olfactory function after experiencing head trauma. When his olfactory function remained anosmic, a ²⁰¹Tl olfacto-scintigraphy showed no migration of ²⁰¹Tl from the nasal mucosa to the olfactory bulb. After treatment with medicines and olfactory training, his olfactory function improved. A second ²⁰¹Tl olfacto-scintigraphy showed an increased migration of ²⁰¹Tl from the nasal mucosa to the olfactory bulb.