OBJECTIVE: to assess population-based caesarean section (CS) rates in rural China and explore determinants and reasons for choosing a CS. DESIGN: cross-sectional study, quantitative and qualitative methods, statistical modelling. SETTING: two rural counties in Anhui province, China. PARTICIPANTS: (a) household survey participants: 2326 women who gave birth in the two counties from January 2005 to December 2006; (b) qualitative study participants: health providers at township and village level and maternal health-care providers (N=58). MEASUREMENTS AND FINDINGS: the household survey were conducted among 2326 women, collecting data on socio-economic and health status and utilisation of maternal health services. Eleven Focus Group Discussions with health-care providers and users to explore perceptions surrounding CS. the CS rate in the two areas were 46.0% and 64.7%. There were complex and different interactions among social-economic and clinical determinants associated with differences in CS rates. The main determinants that emerged were maternal age, maternal education, yearly income, primiparity, uptake of antenatal care and recorded obstetric complications with complex and differing interactions for each county. Maternal fear of pain, worry about mothers' and infants' safety, not satisfied with doctors' competences and physicians' low confidence in vaginal delivery, and absence of a strong midwifery cadre together contributed to final determination of CS. KEY CONCLUSIONS: the CS rates were extremely high in the two counties in rural China. Maternal socio-economic, clinic characteristics and health providers' preference contributed together to the high rates of CS. IMPLICATIONS FOR PRACTICE: evidence-based knowledge and methods to reduce unnecessary CS should be communicated to medical professionals and women. Greater comprehensive attention needs to be paid to a complex pattern of medical, socio-cultural, political and economic contexts of maternity care.