Radiotherapy-induced nausea and vomiting (RINV) are common and troublesome symptoms experienced by patients undergoing radiotherapy. Although quality of life and symptom control now figure prominently in evaluations of cancer therapies, progress in RINV research and clinical prevention has been slow. This article summarizes the major guidelines for the prevention of RINV; their structure, recommendations, evidence base and notable issues. It also examines the current challenges and controversies related to RINV clinical management and research, and provides possible solutions for them that could ultimately lead to better patient care.