Background: Hemorrhage during the operative period is a widespread occurrence in cases undergoing cardiac operations. Hemorrhaging can range from being insignificant and not needing treatment to being severe and potentially fatal. Aim: To evaluate pre-operative anti-platelet therapy as an independent risk factor for perioperative bleeding & blood transfusion. Patients and methods: This prospective controlled randomized clinical trial has been carried out on 32 adult cases who underwent elective surgeries on bypass cardiac surgery at the operative theatre of Suez-Canal University Teaching Hospital from October 2019 to July 2022. Results: There was statistically insignificant variation among the CABG and non-CABG patients in the amount of products of blood transfused either post-bypass or in the first twenty-four hours post-operatively in the ROTEM group and in the classic group. In the ROTEM group, there was a statistically significant reduction in non-CABG patients in terms of blood loss post-operatively (P 0.013). A statistically insignificant distinction has been observed among non-CABG and CABG patients regarding the amount of blood loss post-operatively in the classical group. Conclusion: Anti-platelet therapy may be an independent risk factor for postoperative blood loss, but not for blood product transfusion, and this variable could require future research with a larger sample size.[