The chemical composition of tattooing pigments has varied greatly over time according to available technologies and materials. Beginning with naturally derived plant and animal extracts, to coloured inorganic oxides and salts, through to the modern industrial organic pigments favoured in today's tattooing studios. The demand for tattooing is steadily growing as it gains cultural popularity and acceptance in today's society, but ironically, increasing numbers of individuals are seeking laser removal of their tattoos for a variety of reasons. Organic pigments are favoured for tattooing because of their high tinting strength, light fastness, enzymatic resistance, dispersion and relatively inexpensive production costs. Adverse reactions have been reported for some organic inks, as well as potential complications, during laser removal procedures stemming from the unintentional creation of toxic by-products. Currently, regulatory bodies such as the US Food and Drug Administration have not approved any coloured inks to be injected into the skin, and tattoo ink manufacturers often do not disclose the ingredients in their products to maintain proprietary knowledge of their creations. A methodology was established using micro-Raman spectroscopy on an animal model to correctly identify the constituents of a selection of modern, organic tattoo inks in sit-it or post procedure, within the skin. This may serve as a preliminary tool prior to engaging in Q-switched laser removals to assess the risks of producing potentially hazardous compounds. Likewise, the pigments responsible for causing adverse reactions in some patients may be quickly identified to hasten any corresponding treatment. Copyright (c) 2008 John Wiley & Sons, Ltd.