Samoans are experiencing some of the highest prevalences of obesity and associated health conditions in the world. Sustainable interventions are needed to prevent further increases in obesity. This study describes the cross-sectional association between farm work and adiposity among 754 adults residing in American Samoa in 2002 and 957 adults residing in Samoa in 2003. Adiposity was measured by body mass index (BMI) and percent body fat (% BF), based on bioelectrical impedance. Regression models adjusted for the effects of age, education, occupation (in women), and material lifestyle (MLS), and the clustering within households due to the family design of the parent study. After controlling for these variables, participation in farm work was associated with a significantly lower BMI and % BF in men of all ages residing in American Samoa, women =45 years residing in American Samoa, and women 18–44 years residing in Samoa, and a significantly lower BMI in men 18–44 years residing in Samoa. These results suggest that farm work plays an important role in regulating body size and fatness of adult Samoans and may be ideal for interventions in the Samoan archipelago.