Abstract Background: Patients undergoing complex percutaneous coronary intervention (PCI) carry a higher incidence of in-stent restenosis. This could be due to late acquired malposition, ne-ointimal hyperplasia, increased coagulation activity, in patients having a higher incidence of coronary atherosclerosis, rupture plaque and acute coronary syndrome. Rivaroxiban, selectively targets activated factor X (Xa), which plays a role in the coagu-lation in addition to the mono antiplatelet after 12 months may decrease the complication and improve the outcome of com-plex PCI Patients. Aim of Study: This study aimed to examine the effect of low-dose NOACS (Rivaroxaban 2.5mg twice daily) in addi-tion to a single antiplatelet, for long-term treatment (after 12 months) on patients who underwent complex PCI. Patients and Methods: This study was carried out on 40 patients, with 12 months of post-complex PCI. The patients were collected from Alharm Specialized Hospital Ministry of Health (Alharm, Cairo, Egypt) from December 2021 to Decem-ber 2023. Patients were divided into groups: Group (1) 20 pa-tients treated with a small dose of NOACS Rivaroxaban 2.5mg twice daily and mono antiplatelet (Aspirin 75mg once oral-ly daily or clopidogrel 75mg once orally daily) and group (2) including 20 patients treated with mono antiplatelet (Aspirin 75mg once orally daily or clopidogrel 75mg once orally daily) without adding small dose NOACS, Rivaroxaban all patients in both groups were followed-up for the detection of very late stent thrombosis (after 12 months of complex PCI), in-stent restenosis (ISR), stroke, bleeding, acute Coronary syndrome for one year. Results: The results cleared that minor bleeding occurred in 4 patients (20%) in group I while no cases were recorded in group II. There were two cases of moderate bleeding (10%) in group I while no cases were reported in group II and se-vere bleeding was not recorded in either group. Very late stent thrombosis (after 12 months of complex PCI) was not record-ed in group I but was recorded in group II, where 3 patients (15%). Thein-stent restenosis was not recorded in group 1 and-was recorded in only group 2, in 5 patients (25%). Acute cor-onary syndrome was recorded only in non-treated group II, in 4 patients (20%) and stroke was recorded only in non-treated group II, in one patient (5%). Hospital admission by decom-pensated HF was not recorded in group I and was recorded in the non-treated group (2), in 4 patients (20%). While, sudden cardiac death was recorded in only the non-treated group, in 2 patients (10%). Conclusion: This study concluded that the addition of a small dose of NOAC [Rivaroxaban (Xarelto) 2.5mg twice dai-ly] for long-term treatment to patients who underwent complex PCI, decreased the stent thrombosis, acute coronary syndrome, and stroke without a significant increase in the incidence of ma-jor bleeding, and with increased incidence of minor and mod-erate bleeding.