This study examined trends in overweight (body mass index, BMI ≥ 25.0 kg/m(2)) and underweight (BMI < 18.5 kg/m(2)) from 2001 to 2011 and associations between socio-demographic factors and overweight in 2011 among 15-49-year-old women in Nepal. Nationally representative cross-sectional data were used from three Demographic and Health Surveys conducted in Nepal in 2001 (n = 7,900), 2006 (n = 10,076) and 2011 (n = 5,873). Body weight and height were measured by trained personnel. Data on socio-demographic variables were obtained by interviewing the participants. The data were analysed using logistic regression models. The prevalence of underweight decreased from 26.6 to 18.1 % and the prevalence of overweight increased from 6.4 to 14.0 % between 2001 and 2011 (p < 0.001 for both, adjusted for age, parity and education). Both trends were more pronounced among the rural than the urban women. Although overweight was much more common in the urban (27.4 %) than in the rural areas (11.8 %) in 2011, the difference diminished substantially (odds ratio, OR, for being overweight in the urban vs. in the rural areas, 1.40, 95 % CI 1.15-1.70) when adjusted for other socio-demographic variables. The strongest independent predictors of being overweight were higher relative wealth and advanced age. Overweight has become almost as common phenomenon as underweight among women in childbearing age in Nepal. The urban-rural differences have slightly narrowed and overweight is still related to a higher socio-economic status in this population. Strategies to prevent further increases in the prevalence of overweight should urgently be developed and implemented at all levels of the society.