Humanities and Social Sciences Letters 2312-5659 2312-4318 10.18488/journal.73.2020.84.464.480 Humanities and Social Sciences Letters Employee Mentoring, Career Success and Organizational Success Humanities and Social Sciences Letters Humanities and Social Sciences Letters 12-2020 2020 12-2020 12-2020 8 4 464 480 15 Jun 2020 23 Oct 2020 This study investigated how employee mentoring relates to career success and organizational success. This is because employee mentoring, employee career success and organizational success are indispensible in the life of every organization. To fill the existing gap in the current literature, this study intends to determine the presence of mentoring in Nigerian firms and the extent to which it has helped in both career success and organizational success. The study employed a survey method of data collection through questionnaires administered to 345 respondents, and descriptive statistics and t-tests were used for the analysis and hypothesis testing. This study proposes that there is a significant presence of mentoring in firms throughout Nigeria, that mentoring has a significant positive effect on career success, and that career success has a significant positive effect on organizational success. The study recommends that organizations should incorporate employee mentoring programmes in their plan, which will lead to employees’ career success and organizational success, and the study concludes that mentoring is invaluable to both career success and organizational success.