This volume presents an overview of some recent developments on the absolute stability of nonlinear control systems. Chapter 1 introduces the main tools and the principal results used in this book, such as Lyapunov functions, K-class functions, Dini-derivatives, M-matrices and the principal theorems on global stability. Chapter 2 presents the absolute stability theory of autonomous control systems and the well-known Lurie problem. Chapter 3 gives some simple algebraic necessary and sufficient conditions for the absolute stability of several special control systems. Chapter 4 discusses nonautonomous and discrete control systems. Chapter 5 deals with the absolute stability of control systems with m nonlinear control terms. Chapter 6 devotes itself to the absolute stability of control systems described by functional differential equations. The book concludes with a useful bibliography. For applied mathematicians, and engineers whose work involves control systems.