Soil-transmitted helminths (STHs) are parasitic intestinal worms that infect more than two out of every five schoolchildren in rural China, an alarmingly high prevalence given the low cost and wide availability of safe and effective deworming treatment. Understanding of local knowledge, attitudes, and practices regarding STHs in rural China has until now, been sparse, although such information is critical for prevention and control initiatives. This study elucidates the structural and sociocultural factors that explain why deworming treatment is rarely sought for schoolchildren in poor villages of rural China with persistently high intestinal worm infection rates. In-depth, qualitative interviews were conducted in six rural villages in Guizhou Province; participants included schoolchildren, children’s parents and grandparents, and village doctors. We found evidence of three predominant reasons for high STH prevalence: lack of awareness and skepticism about STHs, local myths about STHs and deworming treatment, and poor quality of village health care. The findings have significant relevance for the development of an effective deworming program in China as well as improvement of the quality of health care at the village level.