Purpose: Reporting adverse events is a critical element of a clinical trial publication. In 2003, the Consolidated Standards of Reporting Trials (CONSORT) group generated recommendations regarding the appropriate reporting of adverse events. The degree to which these recommendations are followed in oncology publications has not been comprehensively evaluated. Methods: A review of citations from PubMed, Medline, and Embase published between Jan 1, 2009 and December 31, 2011, identified eligible randomized, controlled phase III trials in metastatic solid malignancies. Publications were assessed for 14 adverse event-reporting elements derived from the CONSORT harms extension statement; a completeness score (range, 0 to 14) was calculated by adding the number of elements reported. Linear regression analysis identified which publication characteristics associated with reporting completeness. Results: A total of 175 publications, with data for 96,125 patients, were included in the analysis. The median completeness score was eight (range, three to 12). Most publications (96%) reported only adverse events occurring above a threshold rate or severity, 37% did not specify the criteria used to select which adverse events were reported, and 88% grouped together adverse events of varying severity. Regression analysis revealed that trials without a stated funding source and with an earlier year of publication had significantly lower completeness scores. Conclusion: Reporting of adverse events in oncology publications of randomized trials is suboptimal and characterized by substantial selectivity and heterogeneity. The development of oncology-specific standards for adverse event reporting should be established to ensure consistency and provide critical information required for medical decision-making.