Clinimetrics is a methodologic discipline that focuses on the quality of clinical measurements, for example, diagnostic characteristics and disease outcomes. Different clinimetric properties, such as reproducibility and responsiveness, are important in both the development and the evaluation of measurement instruments. This article presents a number of the current challenges in clinimetrics: there is much confusion with regard to terminology, clinimetric properties are population and situation-dependent, and the abundance of different measurement instruments in specific fields hampers the comparison of study results. Further challenges lie in the improvement of the quality of both the measurement instruments and the performance of the actual measurements, and the assessment of the suitability for use in clinical practice. From the perspective of evidence-based medicine, it is essential to have measurement instruments that make it possible to detect clinically relevant improvements that are due to diagnostic and therapeutic interventions. Close collaboration between clinicians, statisticians, epidemiologists, and psychologists is necessary to guarantee healthy future developments in clinimetrics, serving the needs of both clinical research and clinical practice.