During the 1960s and 1970s, the notion that the uterus is a useless and pathological organ after a woman has had ‘enough’ children emerged alongside news reports of excessive hysterectomy in Taiwan. This notion and hysterectomy became two sides of the same coin, the former pointing to the burden of birth control and cancer risk, and the latter to sterilization and removing cancer risk. I explore how, in post-war Taiwan, the notion became commonplace through the intersection of three historical formations: the medical tradition of employing surgery to manage risk (such as appendectomy for appendicitis), American-dominated family planning projects that intensified the surgical approach and promoted reproductive rationality, and cancer prevention campaigns that helped cultivate a sense of cancer risk. The gender politics operating in the family planning and cancer prevention projects were apparent. The burden of birth control fell mainly on women, and the cancer prevention campaign, centring almost exclusively on early detection of cervical cancer, made cancer into a woman’s disease. I argue that the discourses of reproductive rationality and disease risk were parallel and, in several key ways, intersecting logics that rendered the uterus useless and pathological and then informed surgeons’ practice of hysterectomy. Exploring the ways in which the uterus was envisioned and targeted in the history of medicine in Taiwan, this paper shows overlapping bio-politics in three strands of research in an East Asian context – namely women’s health, family planning and cancer prevention – and offers a case for global comparison.