Background: In 2004, in an attempt to address the current obesity epidemic, the United States Department of Health and Human Services announced a strategy to focus on educating the public on the concept of energy balance. The premise of "Calories Count" was that energy balance is primarily a function of calories in (energy in food) versus calories out (energy for physical activity). Purpose: The purpose of this study was to gain further insight into the accuracy of perceived energy expenditure for various intensities of physical activity. Methods: Over 600 individuals (21- 64 years of age), identifying themselves as Hispanic, were recruited from sites of the Department of Motor Vehicles in Miami, Florida. Participants were surveyed in English by a Hispanic interviewer and asked to provide information on their age, education, leisure time physical activity, height and weight. Participants were also asked to report how many calories they used/expended for ten standard physical activities. Results: Overall, only 30% of the participants accurately assessed their energy expenditure. The range in estimated calories for sedentary and vigorous physical activity for one hour was 0 to 4,000, and 0 to 20,000 calories, respectively. A majority of the participants underestimated energy expenditure for most activities. There was a significant (p less than 0.001) relationship between education and accuracy. Discussion: These findings suggest that further efforts are needed to educate at-risk populations about the "Calories Count" approach and energy balance. Translation to Health Education Practice: Future efforts should be made in collaboration with community gatekeepers to determine culturally sensitive methods to teach the public about: (1) the caloric value of various daily physical activities based on the duration and intensity of the activity in reference to body weight; and (2) the concept of energy balance and the component of physical activity. (Contains 2 tables and 1 figure.)