Financing decisions are vital for the financial welfare of the firm. A false decision about the capital structure may lead to financial distress and eventually to bankruptcy. The management of a firm sets its capital structure in a way that firm’s value is maximized. However, firms do choose different financial leverage levels in their effort to attain an optimal capital structure. Although theoretical and empirical research suggests that there is an optimal capital structure, there is no specified methodology, yet, that financial managers can use in order to achieve an optimal debt level. However, financial theory does provide some help in understanding how the chosen financing mix affects the firm’s value. This collection of papers shed light on various determinants of capital structure. With a particular emphasis on Greek examples, this e-book will enlighten the darksome scientific area of the capital structure determination.