The importance of the capital structure as a measure of company growth and performance has been at the core of vigorous debate for many years. With the threat of the recession and global competitiveness to the survival of organizations, what constitutes an optimal capital structure had to be interrogated. The focus of the study is to investigate the factors (with more emphasis on size) that influence the capital structure of manufacturing firms in general and South African manufacturing firms in particular. The aim is to advance recommendations on policy formulation so as to improve the financial performance of the manufacturing sector in South Africa, a developing economy. The study is explained within the theoretical framework which relates elements purported to have an influence on the capital structure to the use of leverage/debt by organizations. Leverage is seen to increase the shareholders‟ interest whilst being exposed to financial risk. The size of the organizations as a comparative element defines the extent of accessing the borrowed funds, hence the distinction between the Small, Medium and Micro Enterprises (SMMEs) and large sized enterprises (LSEs). The research evidence indicates that SMMEs are characterized by lower liquidity, use more short-term debt instead of use of long-term debt, and are generally low in debt and basically capital intensive. On the contrary LSEs are highly leveraged. The selected research design is triangulated, with a combination of a case study which is of a qualitative and interpretive nature, as well as a quantitative type survey by means of a structured questionnaire. Twenty five ratios were computed from information derived from the financial statements of organizations and means and medians were determined for comparative reasons. The questions were directed to chief financial officers or managers responsible for the compilation of the financial statements, mainly to expand on the debt policy of iv their respective organizations. The findings confirmed the correlation between gearing and size, asset structure and growth with the exception of profitability. On the relevance of financial policy regarding debt, two factors were proven to be influential to capital structure decisions: the theory and practice of capital structure and the impact of the debt policy, both of which relate to financial flexibility. The study concluded that as much as there are similarities/consistencies between the two size groups, there are fundamental differences confirming that size significantly impacts on the capital structure choice specifically the use of debt. It is, therefore, recommended that the South African government should review its policies with regards to the financial support towards SMME viability.