The present paper attempts to provide a picture of Himalayan polyandry on the basis of empirical information gathered through the course of a short filed study. The study was conducted in Tangin, a village in Humla District, north-west Nepal. It assumed the hypothesis that polyandry is an outcome of adaptability in the ecological setting of the Himalaya, and the present environmental degeneration and a growth tendency towards monogamous marriage have made people's adaptability to present conditions a matter of serious concern. This study explores how the ecosystem shaped the lives and culture of the Humli people, the ecological factors underlying the practice of polyandrous marriage in the Himalayan region of Nepal with reference to Humla, and the major causes of environmental degradation and its consequences for adaptation and survival.