Main objectives of the present study were to examine (i) the accuracy of using female college students' self-reports of weight and height in estimating rates of overweight and (ii) whether dietary restraint or Body Mass Index (BMI) was the most important predictor of weight underestimation. Participants were 209 female college students who were asked to report their weight and height on a questionnaire, while they were not told that their weight would be verified. Self-report screening was highly specific (98.9%) in identifying cases of normal weight, but only moderately sensitive (48.3%) in identifying cases of overweight. While dietary restraint was not an important predictor of weight underestimation, a higher BMI was an important predictor of weight underestimation. Our findings indicate that heavier female college students strongly underestimate their weight and that exclusive reliance on self-reports of weight and height can lead to erroneous prevalence estimates of overweight among female college students.