Background and aims: Maternal overweight and obesity are increasing worldwide, including Nepal. This study assessed BMI trajectories from early pregnancy to one year postpartum and trends in overweight and obesity over the past two decades in Bhaktapur, Nepal. Methods: In the most recent study, BMI was measured in 800 Nepalese women at three time points: at early pregnancy, 6 and 12 months postpartum (2017-2021). The prevalence of undernutrition, overweight, and obesity was estimated using the World Health Organization and the Asian specific cut-offs. Long-term trends were assessed by comparing these findings with three population-based studies conducted in Bhaktapur between 2001 and 2021 among 2400 women at similar life stages. Results: Mean (SD) BMI increased from 23.7 (3.0) kg/m^2 in early pregnancy to 26.1 (3.3) kg/meter squre at 6 and 25.2 (3.3) kg/m^2 and 12 months. The prevalence of overweight increased from 32.9% in early pregnancy to 48% at 6 months. Using the Asia-specific cut-offs, the prevalences were higher. Results from the three previous population-based studies demonstrated an upward trend where postpartum overweight increased from 11.4% in 2001- 2002 to 44.6% in 2017- 2021. The obesity prevalence rose from 1.8% to 10.9% during this period. Conclusion: Overweight and obesity among Nepalese women have risen dramatically over the past two decades, with postpartum overweight increasing nearly fourfold and obesity more than sixfold. These findings highlight the need for interventions to prevent excessive weight retention and reduce adverse health outcomes.