We performed periodical foot care intervention including nail drilling combined with topical antifungal application for 6 months or more in 24 diabetic patients with onychomycosis who were not receiving oral antifungals, and evaluated its effects. The type of onychomycosis was superficial white onychomycosis (SWO) in eight patients, and distal-lateral subungual onychomycosis (DLSO) in 16. The state of onychomycosis was evaluated according to the Scoring Clinical Index for Onychomycosis (SCIO). Of the eight patients with SWO, none showed aggravation of the onychomycosis state, and two were cured 6 months after the initiation of intervention and two after 1 year (total of four patients, 50%). In the patients with DLSO, the SCIO score was 18.1 +/- 6.5 before intervention but significantly decreased to 14.6 +/- 6.6 6 months after intervention. In 12 patients who we were able to consecutively follow up for 1 year, the SCIO score also significantly decreased compared with the score before intervention. Thus, foot care intervention including nail drilling combined with topical antifungal application had effects on onychomycosis and achieved cure in some patients with SWO. In addition, intervention increased patients' awareness of foot care, showing educational effects. Therefore, foot care intervention including nail drilling may be useful.