This paper examines the determinants of capital structure decisions of firms in the manufacturing industry in Nigeria. The capital structure of a firm consists of a particular combination of debt and equity issues to relieve potential pressures on its long-term financing. To examine such issues, many theories have been developed in the literature and they generally focus upon what determinants are likely to influence the leverage decisions of the firms. This paper examined directly detailed background information of manufacturing sector in Nigeria with the aim of discovering major determinants of its capital structure. And the basic determinants of capital structure in the firms identified by various studies are tangibility, size, growth opportunities, profitability and non-debt tax shields. In addition to these, issues such as corruption, political atmosphere, nature of financial markets, have also been identified as influencing seriously the capital structure of firms in Nigeria. The paper also highlighted issues such as financial distress, bankruptcy threats, solvency problem, risk of default etc dueto unstable economic and political situations as possible dangers that may plague firms whose capital structure may tilt more towards debt financing.