Recent advances in enzyme typing of root sheath cells have significantly increased the evidential value of hair examinations. However, arguably the majority of hairs examined in forensic science laboratories have no sheath cell material and attempts to individualise these hairs rely on detailed microscopic examination. It has been claimed that microscopy is highly subjective and that the variability of microscopic features is too great to allow individualisation of head hairs. This paper reviews a range of microscopic characters with suggestions aimed at improving the objectivity of hair examination which would allow large scale trials and the collection of population data to be carried out. Only then can a true evaluation of the worth of microscopic analysis of hair be made.