One of the main development goals of Nepal is to reduce the number of chronically undernourished people all over the country by half by the year 2015. In consonance to this, this study examines food security and its relationship with socio-economic characteristics among rural households in the remote western mountains of Nepal. Accordingly, the relationship between household's resource endowment and food security status was analyzed based on the calorie requirement for all household members according to their sex and age. The food security measures applied in this paper are Head Count Method, Food Insecurity Gap, and Squared Food Insecurity Gap to capture successively more detailed aspects of the food insecurity status of the household. It was found that majority of the households in the region are food insecure and depth and severity of food insecurity varies according to socio-economic characteristics of the households. Resources are disproportionately distributed in favor of higher castes and these groups are more food secure as compared to lower caste people. As compared to food insecure households food secure households have small family size, lower dependency ratio, higher percentage of irrigated land, and more total land and livestock holdings. Hence, it is concluded that food security strategies should consider socio-economic characteristics of households in order to achieve more than a marginal reduction in the number of chronically undernourished people.