Objective: To determine the predictive value of frequency-doubling threshold perimetry for glaucoma in a population- based study. Methods: The Beijing Eye Study, a population- based study on subjects 40 years or older, included an ophthalmic examination with fundus photography and frequency-doubling threshold perimetry. Glaucoma was defined by a glaucomatous optic disc appearance. Results: The study population consisted of 4349 subjects ( 8615 eyes). Among 207 glaucomatous eyes ( 2.4%), 74 ( 35.7%) did not show any abnormality on frequency-doubling threshold perimetry, suggesting a diagnostic sensitivity of 64.3%. In the total study population, a visual field defect was found in 905 eyes ( 10.5%). In 133 ( 14.7%) of these eyes, a glaucomatous appearance of the optic disc was detected, and 772 eyes ( 85.3%) had a nonglaucomatous optic disc appearance ( either normal or with nonglaucomatous optic nerve damage, retinal disease, corneal disease, or cataract). For 450 eyes ( 49.7%) with a visual field defect, the cause of the perimetric defect was not detected. Conclusions: In a population- based study, frequency-doubling threshold perimetry has a sensitivity of about 64% to detect glaucoma. If the result is abnormal, the probability of glaucoma is about 15%. When results of frequency-doubling threshold perimetry are abnormal, the cause of the visual field defect may not be detectable in 50% of subjects.