As barriers to engaging physical activities or consuming healthy foods increase, the frequency of reported exercise and consumption of healthy foods decreases. The purpose of this study was to develop an instrument that would assess barriers preventing adult Women, Infants, and Children (WIC) clients from engaging in physical activities and eating healthy foods. WIC participants in five Kansas counties were asked upon arrival to their appointments to complete a survey, the WIC Nutrition and Exercise Survey 3 (WNES 3), that assessed barriers to engaging in physical activity and eating healthful foods. A sample (n = 176) of the 1,624 returned surveys were analyzed for concurrent validity. Six primary factors emerged as barriers to engaging in physical activities and consuming healthy foods: food selection, access, positive prompts, exercise knowledge, health knowledge, and intentional behaviors. The highest factor correlation (0.46) was between food selection and exercise prompts, explaining 21% of the variance. For seven of the eight hypotheses developed to test the concurrent validity of the instrument, the null hypothesis was rejected. The WNES 3 has relatively strong concurrent validity and can be utilized in WIC clinics as a tool to assess WIC clients’ barriers to engaging in physical activities and eating healthy foods. The tool could assist WIC clinics in becoming more responsive to their low-income clients’ physical activity and nutritional needs.