This article examines the extent of nontariff barriers (NTBS) to the visible imports of sixteen industrial countries. It user three alternative measures to show that governmental commodity-specific border measures affect more than 27 percent of all imports and more than 34 percent of imports from developing countries. It also shows that during the period from 1981 to 1983, NTBS became significantly more extensive. Detailed statistics reveal considerable variations in NTB coverage by commodity, type of barrier, importer, and exporter. The data on which these conclusions are based were compiled from official information at the highest level of disaggregation and are described in the article.