Psychogenic nonepileptic seizures (NES) are somatic manifestations of psychological distress. There is some evidence that weight problems are more common in patients with psychiatric illness. We have observed that patients admitted for video-EEG monitoring who we diagnosed with NES commonly have a larger body habitus than patients with epilepsy. The goal of this study was to test our hypothesis that there was a significant difference in body mass index (BMI) in patients with nonepileptic seizures compared with their epileptic counterparts. We compared the BMIs of 46 NES patients and 46 age- and gender-matched epileptic controls and found that the NES patients had significantly higher BMIs (30.5 vs 26.1, P=0.006) than controls. This remained true after controlling for weight-gain properties of antiepileptic drugs. These results are compared with the prevalence of overweight and obesity in the general population. Possible explanations of the findings and limitations of the study are discussed.