The call centre industry is gaining momentum in the retail sector, which can be attributed to the fact that many companies use call centre agents to communicate with the end users of their products. A major challenge facing retail companies is finding the right employees for their call centres, so that these people are able to perform according to their natural abilities and acquired skills. The South African retail company under study uses the Clerical Test Battery (CTB2) to screen candidates for its call centre. The aim of this study was to investigate the relationship between the CTB2 numeracy subtest scores and work performance scores of employees in this call centre. The literature review examines the use of psychometric instruments in general, and then focuses on the use of the CTB2 in South African contexts. The objective of the current study was to evaluate the validity of the numeracy subtest when used as part of the selection process for call centre candidates. A quantitative research approach was employed to analyse the raw data, which was already available in the company’s database. The two datasets used were the CTB2 numeracy subtest scores and the work performance scores of 300 call centre agents. The correlation between these two sets of scores was analysed using Statistical Package for Social Sciences (SPSS) software (version 17). No statistically significant relationship emerged between the two research variables. Therefore, it may not be appropriate to use the CTB2 numeracy subtest to screen call centre candidates. The findings of this study suggest that the CTB2 should not be used in isolation when assessing call centre candidates. Face-to-face interviews should form an important part of the decision-making process, and the use of additional instruments to measure general cognitive aptitude and skills such as perceptual speed and accuracy is recommended. The dissertation concludes by outlining the limitations of the study and giving some suggestions for future research in this field.