Background: Mexican American women have the highest leisure-time physical inactivity prevalence of any ethnic minority group. Purpose: This study examined a sample of Mexican American females living near the U.S.-Mexico border to determine whether the variables of age, health status, educational level, marital status, and acculturation distinguished between those who are physically active and those who are physically inactive. Methods: Participants included 379 women ranging in age from 22 to 58 years. Data was gathered through a self-report survey instrument with discriminant analysis used to test for variable differentiation between active and inactive subjects. Results: Present activity was comparable to national representative samples, and the discriminant function indicated higher acculturative status and better perceived health differentiated between those women reporting themselves to be physically inactive versus those reporting to be physically active. Discussion: Physical activity interventions targeting border Mexican American women should account for varying acculturation levels. Translation to Health Education Practice: To be effective, program strategies designed to promote physically active lifestyles among border Mexican American women should be linguistically appropriate and culturally sensitive to optimize behavior change. (Contains 2 tables.)