The prevalence of obstructive sleep apnea (OSA) in women who were being seen for obesity assessment, rather than for assessment of sleep disturbance, was assessed. A consecutive series of referrals to an eating disorders clinic (n = 40) were studied in the sleep laboratory. Their body mass index (BMI) ranged from 29.4 to 66.9 kg/m2. Overnight polysomnograms were carried out, with respiration and oxygen saturation being monitored. Four women (10%), 1 postmenopausal and 3 premenopausal, had significant OSA. They tended to have a higher percentage of body fat and higher BMIs than the nonapnea group. These findings indicate that the prevalence of OSA is higher in the general population of obese women than is generally thought. They highlight the need for professionals who work with obese women to consider the possibility that some of the complaints of fatigue and tiredness may be a result of OSA.