Accurate data on sexual behavior have become increasingly important for demographers and epidemiologists, but self-reported data are widely regarded as unreliable. We examined the consistency in the number of sexual partners reported by participants in seven population-based surveys of adults in the U.S. Differences between studies were quite modest and much smaller than those associated with demographic attributes. Surprisingly, the mode of survey administration did not appear to influence disclosure when the questions were similar. We conclude that there is more consistency in sexual partnership reporting than is commonly believed.