The pelvic organ prolapse quantification system (POP-Q) is currently the most quantitative, site-specific system for describing pelvic organ prolapse. To ensure that anatomic outcomes can be optimally assessed, investigators in the Pelvic Floor Disorders Network evaluated the impact of specific technique variations on POP-Q measurements performed on 133 patients by 16 examiners at seven sites. Values for genital hiatus and perineal body were higher when measured with maximal strain than on resting. With the exception of TVL, internal points did not differ significantly when measured with or without a speculum. The maximum extent of prolapse was best seen with the patient standing. These results suggest that genital hiatus and perineal body should be measured at rest and during straining, as the measurements may assess different aspects of pelvic floor function, and that internal points can be measured with or without a speculum. They also emphasize the value of the standing examination to observe the maximum extent of pelvic organ prolapse.