Electronic Journal of Differential Equations, Vol. 2006(2006), No. 80, pp. 1-8. Title: On the solvability of nonlinear first-order boundary-value problems Author: Christopher C. Tisdell (Univ. of New South Wales, Australia) Abstract: This article investigates the existence of solutions to first-order nonlinear boundary-value problems (BVPs) involving systems of ordinary differential equations and two-point boundary conditions. Some sufficient conditions are presented that will ensure solvability. The main tools employed are novel differential inequalities and fixed-point methods. Submitted April 7, 2006. Published July 19, 2006. Math Subject Classifications: 34B15, 34B99. Key Words: Existence of solutions; boundary value problems; differential equations; fixed-point methods; differential inequalities.