Aim The aim of the present study was to evaluate the clinical characteristics, including floor characteristics and factors, related to severe injury from outdoor falls in older adults. Methods Patients were divided into two groups based on injury severity: the severe group and non‐severe group. The clinical and general characteristics were compared between the two groups, and factors associated with severe injury were investigated. Results Approximately 5% (364/7635) of older people involved in outdoor falls were classified into severe injury. The proportion of men and the rate of alcohol ingestion were higher in the severe group compared with that in the non‐severe group. Falling from stairs was a more frequent mechanism of fall in the severe group compared with that in the non‐severe group. Non‐slippery floor condition had a higher proportion in the severe group than that in the non‐severe group. Head and neck were the predominantly injured regions in both groups. Discharge was the most common result of emergency department treatment in the non‐severe group, whereas admission to intensive care unit was the main result in the severe group. Multivariate logistic analysis showed that male sex and falls from stairs rather than slipping down on the same level were associated with severe injury. Conclusions Floor characteristics did not influence injury severity; however, the risk of severe injury from outdoor falls in older adults was high in men and those who fell from stairs. Geriatr Gerontol Int 2017; ••: ••–••.