The distribution and origin of polycyclic aromatic hydrocarbons (PAHs) in the lichen, Phaeophyscia hispidula (Ach.) Essl., collected from nine different road crossings of DehraDun, capital city of Uttaranchal (Garhwal Himalayas) were studied. The origin of PAHs was also assessed using the Phe/Ant, Flu/Pyr, Ant/Ant+Phe, Flu/Flu+Pyr and Naph/Phen concentration ratios. The total concentration of 16 PAHs ranged from 3.38-25.01 mug g(-1) with an average concentration of 12.09 +/- 9.38 (SD). The PAH ratios clearly indicates that PAH were of mixed origin, a major characteristic of urban environment. Significantly higher concentration of phenanthrene, pyrene and acenaphthylene indicates road traffic as major source of PAH pollution in the city. The study establishes the utility of P. hispidula as an excellent biomonitoring organism in monitoring of PAH from foot hill to sub temperate area of the Garhwal Himalayas.