BACKGROUND: Rivaroxaban is an oral direct factor Xa inhibitor that has been marketed worldwide since 2008 for the primary and secondary prevention and treatment of thromboembolic disorders. Although liver injury was observed in premarketing trials of rivaroxaban, there are no published postmarketing cases of liver injury associated with rivaroxaban. METHODS: Report of 14 cases of liver injury associated with rivaroxaban, including two with liver biopsy, and search queries in three large international pharmacovigilance databases for comparable cases. RESULTS: Formal causality assessment classified rivaroxaban as the "highly probable", "probable" and "possible" cause in 4, 7 and 3 patients, respectively. Search results from three large international pharmacovigilance databases revealed a considerable number of additional hepatic adverse events where rivaroxaban was reported as a suspected cause. CONCLUSIONS: We interpret the presented information as a relevant safety signal that should be followed by pharmacoepidemiological studies in order to reliably estimate absolute and relative risks of liver injury associated with rivaroxaban in support of rational risk-benefit assessment. Meanwhile, incident symptoms and signs of liver disease in patients treated with rivaroxaban should be considered as a potential adverse drug reaction, and if no other likely cause can be identified rivaroxaban should be stopped as soon as possible. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.