In English-speaking countries, the circumcision rate has been declining or is already fairly low; e.g., <5.6% for England and <2% for New Zealand [8, 9]. Even in the US, a steady decline in the neonatal circumcision rate has been reported [6]. To our surprise, we found that the circumcision rate decreased substantially in South Korea, much more than in the US. Both the rapid increase in the period from 1980–2000 and the recent decrease are more drastic when compared to their counterpart periods in US history. In the present study, the current circumcision rate of 75.8% (ages 14–29) is 11.1 percentage points lower than the 86.3% value observed in 2002. This decrease of 10.5% per decade is about two times faster than that reported in a US neonatal circumcision rate study by Zhang et al. [6], which reported a decline of about 5% for the last decade. The percentage of boys circumcised in the last decade was only 25.2%, which is a dramatic decrease compared to the 75.7% reported in 2002. This result strongly suggests that the majority of currently circumcised males underwent the procedure prior to 2002.

Using a questionnaire included in our survey, we identified the wide range of information that has become newly available over the last decade as the chief cause of this decline in circumcision. It is interesting, however, that the vast majority of the information available has been and still is about the benefits of circumcision and the active promotion of the procedure for males of all ages. The change observed in the last decade is that, prior to 1999, 100% of the information was pro-circumcision, including the best age for circumcision, the sexual enhancement gained through circumcision, increased hygiene, medical benefits, etc. Only after 1999 has some information against circumcision become available. Therefore, it is tempting to speculate that the very existence of information about the history of Korean circumcision, its contrary nature relative to a longstanding tradition, its introduction by the US military, etc., has been extremely influential on the decision–making process regarding circumcision. Although only 3% of Korean internet sites, using the most the popular Korean search engine ‘naver’ (http://naver.com), are against indiscriminate circumcision and 97% are for circumcision (data not shown; searched by the authors); these minority sites provide information-seeking individuals sufficient reason to avoid circumcision. It should be mentioned that newspaper articles [10] are less extreme in their promotion of circumcision; only 80% of articles tend to promote the benefits of circumcision.

We discuss the implication of declining circumcision rates in South Korea in view of the diverse global attitudes regarding circumcision. The recent increase in the circumcision rate through mass-circumcision in sub-Saharan Africa has largely been driven by the supposed correlation between human immunodeficiency virus (HIV) infection and lack of circumcision. However, despite widespread information on the supposed benefits of circumcision (including the alleged correlation between HIV and circumcision), the circumcision rate in the US has been declining. The present rapid increase in circumcision in such countries [11] as Uganda, Kenya, Botswana, Mozambique, Swaziland, Zambia, and Zimbabwe is analogous to the situation in South Korea in the years between 1960–1990 [1, 2]. Interestingly, Tanzania, which has been a traditionally circumcising country as a rite of passage, is transforming itself into a medically circumcising one [4]. In Rwanda, which is essentially a non-circumcising nation, both medically and traditionally, the medical circumcision is being vigorously pursued [5]. In this respect, African countries such as Rwanda closely resemble the South Korean situation of 50 years ago.

The onset of South Korean circumcision can be pin-pointed to the years 1945–1950, with the ending of Japanese occupation of Korea, and the start of the US military government and the Korean War. The medicalization of circumcision happened between the years 1960–2000, where the circumcision rate soared from 10% to 90%. In South Korea, a large campaign in support of circumcision was aimed at preventing cervical cancer and the spread of the human papilloma virus (HPV), whereas in present-day Africa, the motivation is to prevent the spread of HIV. In addition, only positive information for circumcision was available to Koreans in 1960–2000; this also seems to be the current case in many sub-Saharan African countries. Improved resources in the US and South Korea have rendered it unnecessary to practice mass circumcision; in sub-Saharan countries, the initial rapid increase in circumcision may be overtaken by the human inclination toward body preservation, aided by improved financial resources and standards of living.

The South African situation is interesting, as it is the African country with the highest standard of living but is also the one in which mass-circumcision is being criticized from within [12]. Circumcision in such English speaking countries as Great Britain, Australia, Canada, and New Zealand showed a rapid decline after an initial increase, although the overall circumcision rates were never as high as those in the US. The question is then whether South Africa, being another English speaking country, will follow the trends of these English speaking nations or whether the desire for HIV prevention benefits will cause the South African rate to go higher.

One limitation of the present study is cross-sectional design and non-probability sampling inherent in internet survey using internet sites and emails etc. Similar sampling methods using internet were used in our 2002 study [2]. With wider usage of internet and email in the population, the present study may represent more general cross sectional sampling than the 2002 version. Clearly, further studies involving general population and probability sampling method are needed.