While various examples of rationale or benefits of ascariasis control could justify a necessity of control activity in a community, few practical index other than the e99 Prevalence or intensity of infection has been used to evaluate the efficacy obtained by the control activity. A literature-based retrospective study was undertaken to provide some numerical data on the decreasing morbidity of surgical ascariasis as a consequence of ascariasis control in Korea. A thorough review of literatures (1959∼ 1990) on biliary and other surgical complications of ascariasis reported from general hospitals revealed that their incidence has been decreasing very proportionally to the national figures of its e99 Prevalence and worm burden. For example, according to the remarkable decreases of the prevalence of ascariasis, there is an evident decreasing tendency of the proportion (%) of ciliary ascariasis cases among all biliary surgical patients and the proportion of biliary ascariasis cases among all biliary stone patients in general hospitals. It is highly suggested that the Korean people have been much benefited by the control activity of ascariasis executed at a national scale since 1960s, especially in terms of incidence of biliary and other surgical complications of ascariasis.