Adverse event (AE) reporting in oncology has evolved from informal descriptions to a highly systematized process. The Common Terminology Criteria for Adverse Events (CTCAE) is the predominant system for describing the severity of AEs commonly encountered in oncology clinical trials. CTCAE clinical descriptors have been developed empirically during more than 30 years of use. The method of data collection is clinician based. Limitations of the CTC system include potential for incomplete reporting and limited guidance on data analysis and presentation methods. The Medical Dictionary for Regulatory Activities (MedDRA) is a comprehensive medical terminology system used for regulatory reporting and drug labeling. MedDRA does not provide for severity ranking of AEs. CTC-based data presentations are the primary method of AE data reporting used in scientific journals and oncology meetings. Patient-reported outcome instruments (PROs) cover the subjective domain of AEs. Exploratory work suggests PROs can be used with a high degree of patient engagement and compliance. Additional studies are needed to determine how PROs can be used to complement current AE reporting systems. Potential models for integrating PROs into AE reporting are described in this review. AE reporting methods will continue to evolve in response to changing therapies and growing interest in measuring the impact of cancer treatment on health status. Although integration of PROs into AE reporting may ultimately improve the comprehensiveness and quality of collected data, it may also increase the administrative burden and cost of conducting trials. Therefore, care must be used when developing health outcomes and safety data collection plans.