The present dissertation for a Master`s degree in metrology is related to laboratory quality in the health care sector in general and to public health services in particular, and its purpose is to contribute to the development of reliable measurement practices in the hospital care section within the scope of at least 4 basic aspects: (i) identification of the available metrology legislation in Brazil which, as a rule, is sparsely organized and is not easily accessible to the end-user/practitioner, whose bibliographical research reveals an explicit lack of specialized literature; (ii) analysis of the compiled measurement standards and recommendations for the sector; (iii) diagnosis of laboratory quality in a Central Public Health Care Laboratory (Laboratório Central de Saúde Pública - LACEN)as a means by which to implement an alternative strategy for introducing a quality system in a public health care laboratory based on a new approach that focuses on the quality of the laboratories that comprise the National Network of Official Quality and Health Care Control Laboratories, and the subsequent creation of a type of mechanism that will allow a laboratory to demonstrate its technical competence; (iv) diagnosis of instruments that are employed in hospital services in terms of their conformity to measurement standards based on case studies of scales for controlling the mass of neonates, and of biomedical instruments for measuring blood pressure, as an example of how measurement is controlled in the case of instruments that are widely used in the hospital care environment.Despite the complexity and reach of the Brazilian health care sector, the research that was carried out not only revealed that the technical literature available is insufficient and unsuitable, but also that the measurement provided by laboratories and hospital care equipment are controlled in a high vulnerable manner. The diagnosis that was performed in a typical health care laboratory also brought to light a number of major challenges for the introduction of a laboratory quality system. Apart from the complex political and economic problems that affect the Brazilian health care system as a whole, the limitations associated with measurements are related to (i)the lack of a suitable metrology culture within the sector because this intrinsic factor hampers the implementation of a laboratory quality system and the latter is an essential requirement for proving that a laboratory is technically competent (accreditation), and (ii) the astonishing variety and number of models and types of instruments/equipment that are in use in this sector, which, as a rule, depend on sophisticated calibration procedures and require complex laboratory infrastructures and calibration methods and practices that are not available in the accredited laboratories within the laboratorynetworks that have been implemented in the country. This paper does not propose to exhaust such a broad and complex topic. Rather, its purpose is to consider the examples of two important areas that are clearly vulnerable in traditional sectors whose involvement with metrology does not represent an obstacle to the practitioner/user of the equipment. To this end, the research has focused on (a) the performance of sixteen scales that are available in six maternity hospitals and are used for controlling the mass of newborn infants as a strategy for the orientation of medical diagnoses and (b) the performance results of sphygmomanometers that are used for controlling blood pressure in hospital environments. This paper is part of a more encompassing initiative towards the improvement of laboratory quality in the Brazilian public health care sector and has been developed as a joint effort with the National Agency of Sanitary Vigilance (Agência Nacional de Vigilância Sanitária - ANVISA).