This secondary analysis study examines the relationship between physical activity and symptoms of insomnia among adults with prediabetes (N = 958) from the 2005-2006 National Health and Nutrition Examination Survey (NHANES). The sample of participants were generally obese, middle-aged, and racially diverse. NHANES questions included symptoms of insomnia, sleep duration, and sleep latency. Body mass index (BMI) was calculated from measured height and weight; at least 2 days of ActiGraph activity monitor data determined mean steps walked. Men walked more steps than women; however, women had more insomnia symptoms. There were significant associations between insomnia symptoms and increased sleep latency and decreased sleep duration. Multiple regression analysis showed that younger age, lower BMI, higher self-rated health, high school education, and fewer insomnia symptoms were significantly related to increased steps walked. The findings indicate that insomnia in adults with prediabetes may be a barrier to their adapting an active lifestyle.