The study examined the effect of workplace diversity management on performance of State Universities in Anambra and Enugu States of Nigeria. The specific objectives include; examine the effect of experience diversity on career development and ascertain the effect of ethnic diversity on quality of research output of State Universities in Anambra and Enugu States of Nigeria. The study used survey research design. Population of the study was 2,650 and sample size of the study was 348 using Taro Yamani’s formular. Instrument used for data collection was the questionnaire. The reliability coefficient of questionnaire was 0.70 and this was measured using Cronbach’s alpha coefficient which showed consistency of the instrument. Simple regression analytical tool was used in testing the hypotheses. Based on data analysis, findings revealed that experience diversity had a significant positive effect on career development of State Universities in Nigeria (F (3,184) = 47.403, pv<0.05) and ethnic diversity had a significant positive effect on quality of research output of State Universities in Nigeria (F (3,184) = 4.035; p<0.05). Based on the findings and conclusion reached, the study recommended that universities management should not only be committed to initiate experience workers, but should also uphold its best practice and be highly committed in doing so. And also Universities management should decentralized ethnic components common culture, tradition, customs, routine practice, costumes, beliefs, and values among workers in order to them have equal mind set during discharging of their duties