INTRODUCTION: Although there is considerable interest in the prevalence and impact of sexual problems worldwide, to date only male erectile dysfunction has been studied systematically in Asian countries. AIM: To study the prevalence of sexual problems and associated help-seeking patterns, among mature adults in Korea and to compare the results with those obtained in other Southeast Asian and East Asian countries. METHODS: As part of the Global Study of Sexual Attitudes and Behaviors (GSSAB), a survey was conducted in Korea during 2001 and 2002. Sampling was based on an intercept methodology and 1,200 individuals (600 men and 600 women) aged 40-80 years completed the survey out of 3,691 eligible subjects (response rate of 32.5%). MAIN OUTCOME MEASURES: General health, relationships, and sexual behaviors, attitudes, and beliefs. RESULTS: Ninety-one percent of men and 71% of women had engaged in sexual intercourse during the 12 months preceding the interview. Early ejaculation (33%) and erectile difficulties (32%) were the sexual problems most frequently reported by Korean men; these conditions were more common in Korea than in other Asian regions. Increasing age, physical inactivity, smoking, and prostate disease were significant correlates of erectile difficulties. The sexual problems most frequently reported by women in Korea were lack of sexual pleasure (37%) and inability to reach orgasm (31%). Only 2% of men and women in Korea had talked to a medical doctor about their sexual problems. CONCLUSIONS: Middle-aged and older adults in Korea regard sex as an important part of life and report continued sexual activity. Several sexual problems are highly prevalent in this population, but very few individuals seek medical help for these disorders. This is largely due to believing that the problem is not serious, not being bothered by the problem, difficulties regarding access to or affordability of medical care, and/or a lack of awareness of available treatments.