This document compares the OECD Principles of Good Laboratory Practice (OECD GLP) and ISO/IEC 17025: General requirements for the competence of testing and calibration laboratories. It explainx what are, in general, philosophical differences between the two documents when applied within a GLP and accreditation framework. It is not intended to be a detailed or exhaustive comparison of the technical content of either of the two documents or approaches. The paper also addresses the broad differences between the two documents and provides a brief comparison of GLP compliance monitoring and laboratory accreditation.