Bioanalytical methods employed for the quantitative determination of drugs and their metabolites in biological fluids provide essential regulatory data for bioavailability, bioequivalence, pharmacokinetic and toxicokinetic studies. The quality of these studies is directly related to the underlying bioanalytical data. Data generated by a typical bioanalytical laboratory is submitted to not only the local regulatory agency, but also to multiple regulatory agencies worldwide. Many pharmaceutical companies and CROs are now performing bioanalytical work for global submissions and the regulatory agencies are often reviewing the bioanalytical work performed in other countries. The bioanalytical workplace has become global and therefore needs universal rules for quality and compliance of bioanalysis. This paper provides a historical perspective and insight into the development and evolution of the regulatory guidance for bioanalytical method validation and analysis of samples.