BACKGROUND: Assessing the causality of a drug product-related adverse event (AE) is a very important aspect of pharmacovigilance. However, it is unclear whether AEs are investigated for causality in a hospital setting. OBJECTIVES: The aims of this study were to: 1) evaluate the proportion of AEs for which causality is sought and, 2) list the causality assessment (CA) tools used by healthcare professionals. METHODS: This retrospective study includes 500 randomized patients (125 patients/year) admitted to a tertiary care academic hospital between 2018-2021. Electronic medical records were reviewed and relevant variables were extracted: 1) demographic, 2) hospitalization, 3) drug product, 4) AE and, 5) CA. A descriptive analysis was carried out (median, minimum-maximum, proportion) to characterize our sample. RESULTS: The characteristic of our sample was as follows: median age 69 years old (range: 21-96 yrs), 43.6% female, median comorbidities/patient 4 (0-12), and median hospital stay of 3 days (1-19). We identified a total of 9,568 drug products and 2,541 AEs, among these, 302 (8.4%) were SAEs. No CA (n=0) or CA tools (n=0) were found in our sample. CONCLUSION: In this study, we report that no AEs, whether serious or non-serious, were subject to documented CA.