BackgroundIn urban China, more single women are becoming pregnant and resorting to induced abortion, despite the wide availability of temporary methods of contraception. We developed and piloted a workplace-based intervention to promote contraceptive use in unmarried female migrants working in privately owned factories.MethodsQuasi-experimental design. In consultation with clients, we developed a workplace based intervention to promote contraception use in unmarried female migrants in a privately owned factory. We then implemented this in one factory, using a controlled before-and-after design. The intervention included lectures, bespoke information leaflets, and support to the factory doctors in providing a contraceptive service.Results598 women participated: most were under 25, migrants to the city, with high school education. Twenty percent were lost when staff were made redundant, and implementation was logistically complicated. All women attended the initial lecture, and just over half the second lecture. Most reported reading the educational material provided (73%), but very few women reported using the free family planning services offered at the factory clinic (5%) or the Family Planning Institute (3%). At baseline, 90% (N = 539) stated that contraceptives were required if having sex before marriage; of those reporting sex in the last three months, the majority reporting using contraceptives (78%, 62/79) but condom use was low (44%, 35/79).Qualitative data showed that the reading material seemed to be popular and young women expressed a need for more specific reproductive health information, particularly on HIV/AIDS. Women wanted services with some privacy and anonymity, and views on the factory service were mixed.ConclusionImplementing a complex intervention with a hard to reach population through a factory in China, using a quasi-experimental design, is not easy. Further research should focus on the specific needs and service preferences of this population and these should be considered in any policy reform so that contraceptive use may be encouraged among young urban migrant workers.