Following an overview of the significance and use of hair examinations, guidelines are presented for hair sample collection. These address the collection of a questioned hair sample and a known hair sample. Descriptions of equipment used in hair analysis focus on the stereomicroscope, transmitted light microscope, comparison microscope, and microscope maintenance and performance check. Guidelines for the microscopical examination address the macroscopical and stereomicroscopical examination, transmitted light microscopy, and comparison microscopy. Guidelines pertinent to hair characteristics and other determinations cover human or other animal origin, somatic origin, racial group, and human hair characteristics. Guidelines for the DNA Analysis of hairs encompass the DNA profiling of hairs and preparing hair evidence for DNA analysis. Guidelines are provided for documenting the observations and results that lead to the examiner's conclusions. Guidelines also address the conclusions that may be reached as a result of a microscopical hair examination. The conclusions discussed are the identification of a hair, racial group, somatic origin, and other features; dissimilarity; similarity; and an inconclusive finding. Guidelines are presented for report writing, review, and testimony, as well as quality assurance and proficiency testing. A 187-item bibliography