The capital structure involves the decision about the combination of the various sources of funds a firm uses to finance its operations and capital investments. These sources include the use of long-term debt finance called debt financing, as well as preferred stock and common stock also called equity financing. One of the most important goals of financial managers is to maximize shareholder's wealth through the determination of the best combination of financial resources for a company and maximization of the company’s value by determining where to invest their resources. The study evaluated the effect of capital structure on the financial performance of listed manufacturing companies in Nigeria. The study employed the ex post facto research design. The population of the study consisted of the quoted manufacturing companies in Nigeria made up of 71 companies as of 31st December 2017 according to the Nigeria Stock Exchange (NSE), which formed the entire population of the study. The study employed convenience sampling in the selection of the sampled companies. Data from the research were obtained from the annual reports of the sampled companies. The study adopted descriptive and inferential statistics. The finding of the study indicated that capital structure influences the performance of the quoted manufacturing companies in Nigeria. The study concluded that capital structure has a significant relationship with the financial performance of listed manufacturing companies in Nigeria. The study recommended that management should ensure that proper capital structure is maintained to improve financial performance and to allow for an increase in dividend payment and retained earnings for expansion.