A sample extraction/cleanup and high-resolution gas chromatography−high-resolution mass spectrometry procedure is described and used to routinely quantify the full range of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxanes and dibenzofurans (PCDD/Fs) and di- to octa-homologue groups in samples of 500−1000 m3 of remote/rural European air. The relative standard deviations of sum of toxic equivalents (ΣTEQ) and ΣPCDD/F concentrations from five concurrent samples each of 700 m3 air were 10 and 11%, respectively. Air samples for PCDD/Fs were taken simultaneously at three sites in May 1997: (i) on the remote western Irish coast, (ii) on the northwest coast of England, and (iii) at a regional background site in the northeast of England. For three sampling events where the air passed successively over the two English sites, the increase in air concentrations was used to calculate an emission rate for the mainland United Kingdom land mass; this crude approach gave values of 2−12 g ΣTEQ/day, which is broadly in line with annual primary atmospheric source inventory estimates. For another event, when an air mass moved successively over the north of England to the Irish west coast, atmospheric half-lives were calculated to be 0.3−4 days for different homologues, which is broadly in line with laboratory and theoretical estimates.