The most perpetual challenge in most organizations today is lack of a well-structured career development and employee retention programme. This has heightened the need for career development programmes in order to achieve employee retention in most organizations. While extensive literature exists, career development, the focus has largely been on its influence on performance and productivity, leaving out the role of employee retention. The study thus set out to determine the relationship between career development and employee retention at MTN Nigeria Communications PLC. The study used descriptive, correlation and regression survey designs. The population of this study was a total of 120 employees out of which 98 copies of questionnaires were found valid for the study. A structured questionnaire was used for purposes of data collection and data was analysed using inferential statistics. Results indicate that generally, a majority of respondents are satisfied with career planning at MTN Nigeria Communications PLC as most respondents exhibit conformity to career planning best practices. Training and development are also found to be satisfactory in the study area according to most respondents as indicated by support given to the programmes both by the participants and the firms management. Coaching and mentoring are further found to be moderately to highly practiced at the firm, to which respondents expressed satisfactory levels. Against this background, inferential results further revealed that among other factors, career planning, training and development, coaching and mentoring career counselling, are key influences of employee retention at MTN Nigeria Communications PLC. Together these career development practices facilitate employee engagement and job retention. This in turn reduces turnover and increase productivity at MTN Nigeria Communications PLC.