This article aims at the reviewing results of animal tissues and foods of animal origin monitoring for chemical residues, performed in the National Research Institute in Pulawy, according to the Directive 96/23/EC. In these twenty years, that have passed since the Directive introduction, numerous new regulations, amending the requirements for ongoing research and analytical methods, were published. Implementation of the control measures was possible due to the efficient cooperation between Veterinary Inspection and properly functioning analytical laboratories.