AbstractThis article is the third of a three‐part series that deals with current compliance issues/challenges for bioanalytical laboratories performing analysis for bioavailability (BA)/bioequivalence (BE) studies. Part 1 of this series discusses the application of key elements from the FDA Good Laboratory Practices (GLP) and the current Good Manufacturing Practices (cGMP) regulations as the framework for the implementation of sound Quality Systems in a bioanalytical laboratory to be in compliance with current regulatory expectations. Part 2 discusses recent Food and Drug Administration (FDA) inspection trends for bioanalytical laboratories and provides an overview of the recent FDA 483 observations related to LC/MS/MS method validation issued to bioanalytical laboratories. This current article provides a more in‐depth analysis of the scientific and compliance aspects of different approaches for selected validation parameters of LC/MS/MS bioanalytical methods. Copyright © 2009 John Wiley & Sons, Ltd.