The present paper reports advantages, drawbacks and applications of the main techniques of sample preparation employed during determinations of total mercury and methylmercury in food matrices employing analytical methods such as: cold vapor atomic absorption spectrometry (CV AAS), cold vapor atomic fluorescence spectrometry (CV AFS), inductively coupled plasma mass spectrometry (ICP-MS), voltammetry, neutron activation analysis and others. The use of slurry sampling, solid sampling, microwave assisted extraction, reflux system by cold finger and Vigreux column were discussed. Also a brief text on use of chromatographic techniques for speciation analysis of mercury is presented. A list of 134 references is cited and analytical characteristics of some these procedures proposed are showed as tables.