We assessed the relationship between socioeconomic position (SEP) and under- and overnutrition in Pakistani adults. In 2006, we conducted a cross-sectional study including adult participants ≥20 years of age (n = 3500) residing in district Khairpur in Sindh province of Pakistan. We categorized body mass index (BMI) into <18.5 (underweight), 18.6-22.5 (normal BMI), 23-24.9 (preoverweight), 25-29.9 (overweight), and ≥30 (obese). We assessed the association of SEP based on wealth index measured as quintiles of a linear index derived from household assets and utilities score with categories of BMI through multinomial regression with the use of normal BMI as reference category while accounting for sampling design. After adjusting for age, sex, education level, and occupation, there was no significant association of SEP and underweight, whereas SEP was positively associated with the categories of preoverweight, overweight, and obesity. In comparison with the 1st quintile, those in upper wealth quintiles had significantly greater odds of being preoverweight (4th quintile: adjusted odds ratio [adjOR], 1.47; 95% confidence interval [95% CI], 1.04-2.08; 5th quintile: adjOR, 1.57; 95% CI, 1.12-2.21), overweight (4th quintile; adjOR, 1.97; 95% CI, 1.43-2.72; 5th quintile: adjOR, 2.66; 95% CI, 1.91-3.69) and obese (4th quintile: adjOR, 2.24; 95% CI, 1.37-3.69; 5th quintile: adjOR, 3.65; 95% CI, 2.14-6.22). Shift from under- to overnutrition across SEP groups is occurring in Pakistan. There is a need for re-evaluating national policies and programs to tackle the growing burden of emerging over-nutrition along with rampant under-nutrition.