This paper explores the relationship between capital structure and financial sustainability of a company. It highlights the importance of proper capital structure and its impact on financial sustainability. The paper includes an introduction, literature review, research methodology, data analysis, and conclusion. The research aims to determine how companies can ensure financial sustainability through the incorporation of the capital structure. The objectives include mitigating insolvency risk and determining the ideal debt to equity ratio. The literature review covers the pecking order theory and the importance of retained earnings and debt financing.