This course serves as an introduction to the qualitative theory of ordinary differential equations. In particular, the following topics will be covered: Flow-Box theorem, notions of stability, phase portraits of planar systems, conjugacies between linear systems with constant coefficients, hyperbolic critical points and topological conjugacies, Hartman-Grobman theorem, local stable and unstable manifolds of a hyperbolic critical point, Hadamard-Perron theorem.