Shareholders with a large stake in a company may have greater incentives to monitor and take corrective actions, because they partially internalize the benefits from their monitoring effort. This study examined the impact of concentrated ownership on audit quality as measured by auditors’ tenure of 36 manufacturing companies quoted on the NSE. The sample size was selected using non-probability method of sampling from a population of 185 quoted companies on the Nigerian Stock Exchange. The study adopted experimental research design and secondary data extracted from the audited annual reports of the firms under consideration covering a period 2007 to 2017 was used. The study found that ownership concentration has no statistically significant impact on auditors’ tenure. The study therefore recommends that ownership concentration should be maintained at a controllable level; the insignificant impact of concentrated ownership on auditors’ tenure as evident in this study might be the result of inefficient monitoring by large owners. But when ownership concentration by large ownership is maintained at a controlling level, firm values and other performance parameters become positive which may be as a result of an effective internal control system against the expropriation of resources and exploitation of minority shareholders by large shareholders.