Objectives: To reveal a relationship between bathing and sleep quality making for healthy aging. Materials and Methods: A population based self-administered mail survey was conducted for randomly selected or all independent people without long-term care needs aged 65 and over in 31 municipalities of Japan in 2010. This data is a part of the Japan Gerontological Evaluation Study (JAGES) project. Frequency of bathing using bathtub in summer and winter was asked. Logistic regression analyses were applied to estimate univariate and multivariate odds ratios of bad sleep quality by regular bathing (7 times or more per week for average of summer and winter) adjusting sex, age, equivalized household income, self-rated health, depression, working status, and region. Results: Response rate of the mail survey was 66.3%. The number of people who made a valid answer for bathing was 18,090. Among them, 53.0% did bathing 7 times a week, 44.6% did less than 7 times, and 2.4% did more than 7 times. Odds ratios by regular bathing were shown on the tables. Most of them indicated significantly low risk for sleeping problems. Conclusion: Regular bathing would be helpful to better sleep quality. After the survey, we are now following up the participants for incidence of long-term care needs and death.