Background: cancer related fatigue is a, subjective sense of physical, emotional,rnand/or cognitive tiredness related to cancer that is distressing, persistent and notrnproportional to recent activity and interferes with usual functioning. Though, thernpercentages of patients who experience cancer related fatigue vary across studiesrnranging from 25% to 100% depending on the type of treatment and the type and stagernof cancer. However, there is limited information at the study area as well as atrnnational level about the current topic. Objective: To assess the prevalence andrnfactors associated with cancer related fatigue among cancer patients attending TikurrnAnbessa Specialized hospital in Addis Ababa, Ethiopia, 2020. Methods: Anrninstitution-based cross-sectional study was conducted at Tikur Anbessa SpecializedrnHospital from January 20rnthrn to February 20rnthrn of 2021. It included 406 samples ofrncancer patients by systematic random sampling technique. Data was collected byrnusing pre-tested structured face to face interviewer and collected after obtainingrnwritten consent from the respondents. The data was entered into Epi-info version 7rnand analyzed using SPSS Version 25. Bivariate and multivariate analysis was done.rnAOR and 95% CI was used to see the strength of the association. Independentrnvariables with P-value < 0.05 was considered as statistically significant associationrnwith the outcome variable. Result: A total of 383 participants were included whichrnmakes the response rate 94.3%. The mean age of the respondents was 46.91rn(SD=14.70) years. Among the respondents, the majority were 51 years and abovern(42%) and 61.6% of them were female. Almost three-fourth of the patients werernmarried (70.2%). The prevalence of cancer related fatigues was 72.3%. Patientsrnwho were female (AOR 4.80), single (AOR 5.43), depression (AOR 5.30) and anxietyrn(AOR 2.88) had statically significant association with cancer related fatigue.rnConclusion & recommendation: huge portion of the patients were experiencedrncancer related fatigues. So, health care providers working at oncology units shouldrnhave a continuous/routine screening for cancer related fatigues that will help forrnearly identification patients with the problem and manage it accordingly. This willrnhave its own contribution in improving the health condition of the patients.