Diamond knife sectioning, or ultramicrotomy, is being used increasingly as an attractive alternative or complimentary means of producing quality TEM specimens. This paper represents a first attempt to provide a basic methodology for this technique for materials scientists, point out its drawbacks, provide a comprehensive listing of more than three decades of widely-scattered and ingeneous applications, and illustrate the diversity of these applications with clear examples. Suggestions will be made for further improvements in ultramicrotomy so that it can be applied in a more routine fashion to modern advanced materials or TEM applications involving demanding chemical microanalysis.