Herbarium mosses (Dicranum scoparium Hedw., Hypnum cupressiforme Hedw., Thamnobryum alopecurum Hedw. Gangulee and Thuidium tamariscinum Hedw. Schimp.) from 1879-1881, 1973-1975 and 2006-2007 periods were used to investigate the historical changes of atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) at a remote site located in Northern Spain. The mosses had been conserved in the Herbarium PAMP of the University of Navarra, which contains specimens of bryophytes collected in the Natural Park of Bertiz since 1879. Natural abundance of nitrogen and carbon isotopes was also measured in order to assess the evolution of emissions from anthropogenic sources. Nitrogen concentrations, 13C, 15N and PAH levels were significantly higher in 19th century samples with respect to the present century samples. Moreover, PAH distribution varied over the centuries, following a tendency of light PAH enrichment. The carbon, nitrogen and PAH levels measured in the mosses tissue were related to the historic evolution of anthropogenic emissions in the area, mainly influenced by changes of economic activities, domestic heating and road traffic density. Mosses provided by herbaria seem to offer the possibility to study long-term temporal evolution of atmospheric PAH deposition (Foan et al., 2010).