There is no evidence for effects of gait training in spinocerebellar degeneration (SCD) of SCD severity level IV. Here we report the effect of gait training in a 42-year-old man diagnosed with SCD severity level IV. At the beginning of physical therapy (day X), his Scale for Assessment and Rating of Ataxia (SARA) score was 20 and his Berg Balance Scale (BBS) score was 27. The patient required two people to assist him in walking because of his high risk of falling due to ataxia, which caused the lower limbs to step out in unexpected directions. His Functional Ambulation Categories (FAC) score was 0. Regular standing and balance function exercises failed to improve his condition, and he was switched to physical therapy focusing on gait training using a walker with a saddle (OG Giken Safety Walker GB-500), which improved his SARA score to 15 and BBS score to 35 at day X+24. He became able to walk with the assistance of one person, and with the use of handrails, his 10 m walking speed was 12 s and his continuous walking distance was 60 m. His FAC score also improved to 2, and he was transferred to another hospital to continue his rehabilitation. Even in this patient with SCD severity level IV, intensive gait training using a walker with saddle resulted in improved walking ability.