Abstract. Conditions are established for oscillatory and asymptotic behavior for first-order matrix systems of ordinary differential equations, including Hamiltonian systems in the selfadjoint case. Asymptotic results of Hille, Shreve, and Hartman are generalized. Disconjugacy criteria of Ahlbrandt, Tomastik, and Reid are extended.1. Introduction. The purpose of this paper is to establish conditions for oscillatory and asymptotic behavior for systems of linear homogeneous ordinary differential equations. A detailed definition of the systems involved is given in §2, and for background and motivation the reader may refer, for example, to [7] Matrix notation is used throughout. Matrices of one column are called