Objectives Having a lighter skin tone is highly valued among many Asian women. If skin colour is affected by smoking, women may be motivated to avoid tobacco or quit smoking. The present study examined the association of tobacco smoking with skin colour in Japanese women.

Method Information on smoking habits was obtained through a self-administered questionnaire completed by 939 Japanese women aged 20–74 in Gifu, Japan, during 2003–2006. Skin colour was examined on the inner side of the upper and lower arm and on the forehead using a Mexameter device (a narrow-band reflective spectrophotometer), which expressed results as a melanin index and erythema index.

Results Current smokers had higher melanin indices than never-smokers and former smokers for all measured sites. The number of cigarettes smoked per day, the years of smoking and pack-years were significantly positively associated with melanin indices for all measured sites after adjustments for age, body mass index, lifetime sun exposure, and room temperature and humidity. Smoking was also significantly associated with erythema indices on the inner upper and lower arms.

Conclusions These data suggest that smoking is associated with a darker skin colour. If our findings are confirmed by further studies, they could be used in antismoking campaigns or by smoking cessation services.