Background: The COVID-19 pandemic has created unprecedented disruptions to cancer clinical trial research across the world due to a temporary global suspension of patients’ recruitment to cancer clinical trials. Access to clinical trials permits better treatment options and best clinical practice standards for patients with cancer. We present the impact of the COVID-19 pandemic on cancer clinical trial activity at the Cancer Clinical Trials Unit (CCTU) at the Mid-Western Cancer Centre, University Hospital Limerick (UHL). Over the last 4 years 28 clinical trials, both interventional and translational, have opened here, across a variety of primary disease sites, with 5 trials opened in 2017, 11 in 2018, 7 in 2019 but only 2 in the first 10 months of 2020 until 3 further trials were opened in December. Methods: CCTU records were reviewed to identify the number of patients screened and consented to participate in cancer clinical trials at UHL in 2020, which were compared directly with corresponding numbers for 2019. Results: In 2019, 17 clinical trials were open and recruiting at the CCTU, UHL. During 2020, 19 trials were recruiting although during the 1^st surge of the COVID-19 pandemic recruitment was essentially suspended and CCTU staff were redeployed throughout the hospital. 1^st Six months 2020 vs 2019 In the six months from January 2020 until the end of June 2020, 99 patients were screened and only 15 (15.2%) signed informed consent to participate in a cancer clinical trial. When these figures are directly compared with the first six months of 2019, there is a 33% reduction in patients screened for participation (147 vs 99) and a 60% reduction in patients consented (37 vs 15) to clinical trials. 12 Months 2020 vs 2019 In total during 2019, 376 patients were screened for inclusion to participate and 49 (13%) patients signed informed consent to participate in a clinical trial within CCTU at UHL. In 2020, 914 patients were screened for participation with 51 patients consented to participate (5.6%). The majority (45/51 (88%)) of patients consented to cancer clinical trials in 2020 at the CCTU, UHL were recruited to translational based studies and only 6 (12%) consented to interventional studies compared with 2019 when 30/49 (61%) consented to translational and 30/49 (39%) to interventional studies. Conclusions: During the COVID-19 pandemic, the percentage of patients consented to participation in a clinical trial reduced significantly, as compared to the previous year (5.6% vs 13%). Fewer interventional studies have recruited patients during 2020. As we enter the third surge of COVID-19 infections in Ireland, we must continue to monitor and identify effective strategies to navigate the ever-changing situation for cancer clinical trials, in an attempt to maintain access to high quality cancer clinical trial opportunities for our patients.