BACKGROUND: Setting priorities in oncology is a useful way to produce a robust set of research questions that researchers can address. OBJECTIVE: The aim of this review was to describe cancer nurses and patients' main research priorities and describe their development over time. METHODS: A mixed-method systematic review was conducted for the period from 2000 to 2018 through a search of multiple databases. The methodological quality of the studies included was assessed using the Mixed-Methods Appraisal Tool, and the process of setting the health research priorities was assessed using Viergever's tool. Each study's top research priorities were extracted and summarized in categories. RESULTS: Fifteen studies were included: 13 addressed nurses' research priorities, and 2 focused on those of patients. The majority were Delphi and quantitative studies that were conducted in the United States and United Kingdom. The quality criteria score and the quality of the process were considered sufficiently good. The most important research priorities were categorized as disease control and management, patient-related issues, and professional dimensions and issues. Management of symptoms and pain, education, information, and communication were research priorities always present in the articles during the study period. CONCLUSION: Priorities change over time and depend on several factors; however, some have remained consistent for the last 18 years. Although there is increasing emphasis on including patients in establishing research priorities that inform cancer care, this involvement is still lacking. IMPLICATIONS FOR PRACTICE: Future studies should describe the primary cancer research priorities of nurses in collaboration with patients.