Biomedical science is a sensitive discipline and presents unique challenges due to its social character, continuous development and competitiveness. The issue of quality management systems and accreditation is gaining increasing interest in this sector. All over Europe, Health Services Units have started to introduce quality management systems and harmonization of criteria for accreditation is of increasing importance. Moreover, clinical laboratories, like the Assisted Reproduction laboratories and biochemical laboratories are required to apply a Quality Management System in order to ensure their correct, scientific and effective operation. Ultimately, it is a moral obligation for every health care organisation to supply the best possible care for the patient. The specific features and the diversity of clinical laboratories led to the introduction (2003) and, recently to the revision (2007) of the international standard ISO 15189, which is the first international standard developed specifically to address the requirements for accreditation of this type of laboratory. The basic principles for the quality assurance in the clinical laboratories are: center dot Complete and unambiguous standardized operating procedures. center dot Complete and unambiguous directives of operation. center dot Obligatory detailed written documentation, i.e., how each action is done, who will do it, where will this action take place and when. center dot Suitable scheduling of calibration/control/preventive maintenance of laboratory equipment and recording of each activity. center dot Distribution of responsibilities among the staff and continuous education and briefing according to current scientific data. center dot Complete and informed record file keeping. center dot Continuous improvement which is monitored with the adoption of quantified indicators. center dot Internal and external audit of all activities. center dot Troubleshooting. All these principles should be supported by the Management in order that the necessary adaptations should be made in the provision of human resources, equipment, supplies and working environment and the resolution of organisational problems. This article deals with the planning and the implementation of a Quality Management System, in accordance with ISO 15189 (2007), in the Assisted Reproduction Laboratory in one of the biggest Maternity Clinics in Greece. The benefits resulted; both for medical laboratory service and patients are also presented and discussed.