A combination of agro-ecological and socioeconomic factors gave rise to the current weed epidemic of Phalaris minor, threatening the sustainability of wheat (Triticum aestivum) production and rural livelihoods across a large area of the Indo-Gangetic plains in northern India. This paper presents the results of a system audit describing the current status of the P. minor epidemic in Haryana State, India, in a broad agronomic and socioeconomic context. The audit showed that the P. minor epidemic is a major production constraint for many farmers, and seriously affects farm profitability. It suggests that the epidemic is closely entangled with geographic factors, as well as farm management systems and farmers' socioeconomic positions. Since the farmer community is not a homogeneous group with respect to P. minor management, nor in ability to change farm management practices, farmers are not equally receptive to technical innovations aimed at improving sustainability of wheat production.