This is a brief compilation of criteria on analytical quality that are prerequisites for the establishment and use of reference intervals in laboratory medicine. In this context, analytical quality is characterized by the precision, accuracy and long-term stability of laboratory methods performed with diagnostic kits, including their application on various instrument platforms. Systematically, analytical quality can be differentiated into quality of the method and its performance, and quality of long-term use. Factors influencing these types of quality in the development of diagnostic kits are discussed. The responsibility for maintaining analytical quality is shared by the two parties involved in the provision and use of reference intervals: The manufacturers of diagnostic kits are committed to providing complete description and traceability of their methods, whereas users must consider the effects of physiological, biometrical, preanalytical and analytical influences on the reference interval.