Background: According to World Health Organization (WHO) June 2 report there were total ofrn172,173,283 cases and 3,695.990 deaths and, 154, 832,586 recovered with the highest prevalencernin the United States America. Cardiovascular and arrhythmic events have been reported inrnhospitalized COVID-19 patients. COVID-19 has the potential to cause myocardial injury andrnnoted to have heart failure in a study of inpatients from previous studies. There are researchesrnlimitation regarding the prevalence and associated factors of the disease in general andrnparticularly among COVID-19 critically ill patients. Understanding the situation in Ethiopiarnwould help to us to improve their status and outcome of clinical service. rnObjective: To assess the Prevalence and associated factors of cardiac arrhythmia amongrncritically ill COVID-19 patients in Eka Kotebe COVID-19 center Addis Ababa Ethiopia, 2020. rnMethod: A Cross-sectional study was applied among 388 sampled medical records of COVID19rnrnpatients at Eka Kotebe hospital. The study periods were from February 25-April 30, 2021. rnSample size was calculated by using single and double population proportion formula, A pretestedrnandrnstructuredrnrecordrnreviewsrnchecklistrnwasrnusedrntorncollectrndatarnandrntherndatarnentryrnandrndatarnrnanalysisrnrnwas done by statistical software like EPI data and SPSS. Bivariable and multivariablernbinary logistic regression was used to examine the relationship between the dependent andrnindependent variables. rnResult: The prevalence of cardiac arrhythmia among critically ill COVID-19 positive patientsrnwith 91.5% response rate was found to be 71.4%. Presence of comorbidity (AOR: 11.00 95%CI;rn5.57, 21.70), substance use (AOR: 2.77 95%CI 1.54, 4.99), hypokalemia (AOR: 6.85 95%CI;rn2.96, 15.86), hyperkalemia (AOR: 9.31 95%CI; 4.75, 18.22) and hypotension (AOR: 2.75rn95%CI 1.27, 5.92) are statistically significant associated factors for cardiac arrhythmia. rnConclusion: High prevalence of cardiac arrhythmia was observed in Eka Kotebe critically illrnCOVID-19positive patients. Presence of underline comorbidity, hypokalemia, hyperkalemia,rnhypotension and substance (chat, alcohol, cigarettes and others) use were significantly associatedrnwith cardiac arrhythmia. Health service organizations have to give attention to monitor vital signrnspecially blood pressure and to monitor electrolyte balance.