We used radio telemetry to study the home range, activity patterns, arboreality and day refuges of the Korean wood mouse Apodemus peninsulae (Thomas, 1907) during fall and winter in a temperate forest in Korea. The mean home range size in fall was 1,998 ± 1,732 m² (range: 599–7,798 m²; n = 14); winter home range size could not be estimated because the mice were minimally active in winter and few movements were identified. Males tended to have larger home ranges than did females, although this difference was not statistically significant. In the fall, Korean wood mice were primarily nocturnal and crepuscular, and they often used several day refuges. Male and female activity levels were not significantly different. No direct evidence of arboreality was found.