The study presents the European Union legislation in force relating to forensic laboratories, in particular the need for accreditation based on international standard ISO 17025. Accreditation is the official third-party confirmation that the laboratory operates in accordance with a documented quality management system and has the competence to perform the laboratory tests mentioned in the accreditation. Rules for accreditation are contained in international standards and guidelines, which specify the requirements for accreditation bodies and agencies under this process. Purpose of accreditation is to: confirm the competence of certification bodies, inspection and testing and measurement, and thus make possible the recognition of products and services to European and world markets and to achieve the acceptance of accredited certificates and test results and calibrations in Europe and globally. The aim of this paper is to present issues of accreditation through the prism of Forensic Laboratory of the Metropolitan Police, taking into account the fact that it is accredited, and detailed discussion of EU legislation relating to that theme.