This study examined the major factors of administrative performance and its influence on supportrnstaff turnover at the College of Natural and Computational Sciences (CNCS), Addis AbabarnUniversity. To address the main objective of the study, four basic research questions wererndeveloped. These were to examine factors of administrative performance of CNCS thatrnaggravated support staff turnover, to assess demographic characteristics of support staff that leftrnthe college during 2006-2009 E.C., the measures the college had taken to reduce support staffrnturnover and to suggest possible mechanisms to reduce turnover at CNCS. The major datarncollection techniques used were survey questionnaires (quantitative and qualitative), interviewrnand document analysis. The major participants in this study were current support and resignedrnstaffs members of CNCS. The total number of current support staff was 497 of which 149rnsamples were selected using simple random sampling technique while the total number ofrnresigned staff was 54 of which 16 samples were chosen using snowball sampling for this study.rnThe major statistical tool employed in this study was descriptive statistics. Frequency andrnpercentage were used to analyze demographic items. The result of the finding showed the trendsrnof support staff turnover that had been increasing from year to year. This finding revealed that therndominant administrative performance factors that influenced support staff turnover were directlyrnrelated to compensation and benefit packages, development opportunities, working environmentrnand job characteristics. To reduce support staff turnover, the college provided incentives ofrnovertime work at certain work units. The college also prepared a special program to providernrewards (laptop, computers, certificates and household furniture) for good performers thatrnmotivate support staff members to stay longer at CNCS, but they were not satisfied with therninvectives and rewards. This brought about continuous turnover of current support staff thatrnaffected overall effectiveness of the college. Hence, CNCS needs to concentrate on improving itsrnadministrative performance packages and emphasizes the magnitude of compensation and benefitrnpackages to boost support staffsâ€™ morale, motivation, performance and retain them longer.