Few studies have examined the association between food insecurity and physical performance among older adults. To our knowledge, the effect modification of smoking status has never been examined in previous studies of food insecurity and physical performance. Using data from the 1999-2002 National Health and Nutrition Examination Survey (NHANES), we examined if the association between food insecurity and physical performance including gait speed and knee extensor power varied by smoking status among a nationally representative sample of men and women (≥50 y). Responses to the U.S. Household Food Security Survey Module (HFSSM) were used to assign participants to study categories. Multiple linear regression models controlling for age, gender, race/ethnicity, education, and income were used. The association between food insecurity and gait speed varied by smoking status (p=0.005). For nonsmokers, those who were marginally food secure (0.91 m/s, p=0.016) and food insecure (0.94 m/s, p=0.004) had significantly slower gait speeds than food secure participants (1.04 m/s). Similar findings were found for knee extensor power. An association between food insecurity and either physical performance measures was not detected among smokers. Given the magnitude of the effects of smoking on physical performance, smoking appears to obscure the relationship between food insecurity and physical performance. ©Taylor & Francis Group, LLC.