Information from patients about their own quality of life, experiences in care, and individual assessments of treatment processes and outcomes are becoming increasingly important. Patient-reported characteristics can refer to subjective information about their own health (Patient-Reported Outcome Measures [PROMs]) or to objective information about their experience during the treatment process (Patient-Reported Experience Measures [PREMs]). This article provides an overview of the similarities and differences between PROMs and PREMs. Subsequently, ways to collect PROMs and PREMs are presented and in doing so, an insight into probabilistic testing theory (item response theory) and computer adaptive testing is given. Using national and international initiatives as examples, the implementation of PROMs and PREMs in health care systems is presented and future implementation strategies are discussed within an outlook.