The last decade international trade in animals and animal products was liberated and confidence in this global trade can increase only if appropriate control measures are applied. As foot-and-mouth disease (FMD) diagnostics will play an essential role in this respect, the Food and Agriculture Organization European Commission for the Control of Foot-and-Mouth Disease (EUFMD) co-ordinates, in collaboration with the European Commission, several programmes to increase the quality of FMD diagnostics. A quality assurance (QA) system is deemed essential for laboratories involved in certifying absence of FMDV or antibodies against the virus. Therefore, laboratories are encouraged to validate their diagnostic tests fully and to install a continuous quality control (QC) monitoring system. Knowledge of performance characteristics of diagnostics is essential to interpret results correctly and to calculate sample rates in regional surveillance campaigns. Different aspects of QA/QC of classical and new FMD virological and serological diagnostics are discussed in respect to the EU FMD directive (2003/85/EC). We recommended accepting trade certificates only from laboratories participating in international proficiency testing on a regular basis.