There are numerous studies made on the determinants of audit quality, but their findingsrnand conclusions are inconsistency or inconclusive implying the need for further researchrnin the same area. Besides, internal control of auditee and number of staffs assigned in anrnaudit engagement are under-researched determinants of audit quality. This study, thus,rnanalyzed the determinant of audit quality in private audit firms of Ethiopia taking auditrntenure, audit fee, internal control of auditee, accountability of external auditors, andrnnumber of staff assignment in an audit engagements as determinants of audit quality. Thernstudy adopted a quantitative research approach to test its working hypothesis. The targetrnpopulation of the study were 122 licensed and registered private audit firms in AddisrnAbaba. Primary data were collected from the 55 sampled private audit firms of Ethiopiarnthrough questionnaire and structured interviews. Data from structured interviews werernobtained from the principals/Partners of audit firms. Secondary data were also collectedrnfrom the financial reports of auditees of the sampled audit firms to measure audit qualityrnusing discretionary (abnormal) accrual of management earnings as a proxy. Therncollected data were analyzed by using SPSS Statistics version 25, Linear multiplernregression analysis, and descriptive statistics. The results of linear multiple regressionrnanalysis showed that audit tenure, internal control of auditees, and number of staffsrnassignment per audit engagements have positive and statically significance impacts onrnaudit quality of private audit firms of Ethiopia. While, audit fee and accountability ofrnexternal auditors have statistically insignificance impacts on audit quality of privaternaudit firms of Ethiopia. Accordingly, recommendations to private audit firms, auditeesrnand their shareholders and suggestions for future research are provided.