This paper summarizes the main objectives, areas of collaborative research and scientific achievements of the EC Concerted Research Project “Tissue Characterization by MRS and MRI” (1988-1992). In the field of MRI the Project developed original protocols and test objects for performance assessment and quality control of clinical equipment; b) an image conversion software package for interlaboratory exchange of MR images; c) pilot data bases of in-vitro and in-vivo tissue relaxation times. In the field of MRS, the Project proposed an original test system for performance assessment and quality control of clinical and experimental equipment. Test objects for assessing volume and slice selection signal localization were designed, constructed and optimized in a series of international trials. A multi-center evaluation of different data analysis procedures was also carried out on a set of complex valued in vivo NMR time domain test signals, in order to make quantitative MRS results from different Centers more comparable and reproducible.