Background Patients with diabetes mellitus often have a difficult life, suffering from foot ulceration or amputation. Diabetes is characterized by chronic inflammation, and one of the features of inflammation is hypoxia. Recently, it has been reported that KAI1 is a hypoxia target gene. There is no published research on hypoxia-related KAI1 protein levels in human diabetic skin. Therefore, we have investigated the expression of KAI1 protein in diabetic skin tissue in vivo. Methods The expression of KAI1 protein was evaluated by western blotting in 6 diabetic skin tissue samples and 6 normal skin samples. Immunohistochemical staining was carried out to identify KAI1 expression. Results The western blotting revealed significantly increased expression of the KAI1 protein in diabetic skin tissues as compared to normal skin tissues. Immunohistochemical examination demonstrated that KAI1 was expressed in all diabetic skin tissues with moderate-to-strong positivity and weakly expressed in normal skin tissues. Conclusions Our data suggest that a high expression of the KAI1 protein can be observed in diabetic skin tissue. To the best of our knowledge, this is the first report suggesting that KAI1 protein expression in diabetic skin tissues may be associated with chronic inflammatory states and hypoxia.