Purpose: To investigate self-esteem according to differences between real and ideal Body Mass Index (BMI) in female college students. Methods: Subjects were 587 female students in Korea. Data was collected by using a developed questionnaire through pretesting. Results: Actual number (46.7%) and actual number (5.1%) of participants were defined as being underweight and overweight, respectively. Nearly all participants expression high dissatisfaction with their body shape. Averages of 1.02, 2.97, 7.81 were revealed for underweight, normal weight and overweight group differences between real and ideal BMI. Those who were defined as overweight exhibited significantly self-esteem than those who were defined as underweight. Conclusions: The belief that body shape is heavier than actually the case may be prevalent among female college students in Korea. This difference between the real and ideal BMI negatively influences self-esteem. Programs aimed at improving body image awareness an self-esteem among female college students are needed.