This paper investigates the usefulness of wild boar (Sus scrofa) hair as a non-invasive indicator of mercury pollution. Samples were collected in two hunting seasons (1998/1999 and 1999/2000) by hunters from four differently polluted regions of Poland. Mercury content was determined by AAS methods. Different washing procedures were compared. De-ionised water was found to be suitable for the removal of exogenous mercury sources in hair analysis. Metal distribution along hair was analysed. It was found that problems arising from differences in distribution of metal along a single hair strand as well as differences in the hair colour can be eliminated through the careful homogenisation of the samples before analysis. The influences of physiological, ecological and environmental factors that might significantly affect the obtained results (age, gender, season, location of habitat and diet of the sampled animals) were estimated and taken into account. The present study revealed that female hair contained a higher amount of mercury than male hair. Moreover the highest mercury content was found in young individuals between 1 and 2 years of age. A positive correlation of the present results with environmental data taken from the State Offices showed an influence of environmental pollution on the mercury level in wild boar hair.