Background (problem statement): Population-based cancer registries systematically rncollect information on all new cancer cases in a defined geographic area. The value of cancerrnregistries is highly dependant on the quality of the data that it collects, but the level of data qualityrnfor the population-based cancer registry in Addis Ababa was not evaluated and well understood. rnObjectives: the general objective was to assess data quality status and gaps in Addis Ababa rnpopulation-based cancer registry, Addis Ababa, 2019/2020 rnMethods: Convergent parallel mixed study design with the methods proposed by Bray andrnParkin, and Parkin and Bray (Eur J Cancer 2009;45:747â€“64) was applied to the Addis Ababa rnpopulation-based cancer registry data from 2012 to 2016. Cancer cases registered in the databasernfrom 2012 to 2016 were included in the study, and data were sampled for re-abstracting audit andrntimeliness and the sample size was 408. Polynomial and linear regression, one-way ANOVA, Nonparametricrntest,rnkapparncoefficient,rnandrnIntraclassrncorrelationrnwerernperformedrnusingrnSPSS.rnrnResults: The coding and classification in the registry agreed with international agreements. rnAnnual trends in ASR for both sexes was not linear and exhibited fluctuations, age-specific rnincidence curves in both sexes showed a rapid rise above middle age groups and sharp decline atrnold age, ASR for three most common neoplasms in both sexes was lower than other SSA Countriesrnand childhood incidence rate per 100,000 showed below world reference for males 0-4 and femalesrnage group 5-9 and 10-14. MV% was 87.2% in males and 90.2% in females, the agreement rate inrnthe re-abstracting audit was reasonably high, DCO% was 0.11% in males, and 0.14% in females,rnthe overall proportion of other and unspecified cases was 2.6%. The meantime betweenrnidentification ad registration of cases was 92 days. rnCONCLUSION: the AAPBCR was comparable in using international agreements, there was arnreasonably high level of validity in the registry, with the variability of completeness and delayrnregistration. Budget and ownership were major gaps identified. It was recommended to improvernthe data collection system to active, covering all data sources, and the FMoH to handover thernregistry from owners.