Abstract: The purpose of the study was to assess the impact of age and gender diversity on employee performance in an organisation. A descriptive research design was adopted with Zambia Compulsory Standards Agency (ZCSA) being the focus organisation which has a total of 103 employees from various units. Stratified and random sampling techniques were used to draw a sample size of 50 respondents from various hierarchical levels. The main data collection instruments were self-administered questionnaires and interview guides. A set of descriptive statistics including frequencies, percentages, the mean and standard deviation were used to generate tables, bar graphs and pie charts to present the results of the study using SPSS version18.