The dynamics of vector fields on surfaces is fairly well understood. Starting from dimension 3, one can encounter more complicated and interesting phenomena, like chaotic behaviour for instance. In this series of talks, I would like to give a general introduction to the qualitative dynamics of flows 3-manifolds. I will begin at a very elementary level and I will describe a great number of significant examples. Then, depending on time, I shall discuss the following three aspects : many attempts to describe all Anosov flows and some conjectures, search for periodic solutions, around the former Seifert and Weinstein’s conjectures, Kuperberg example, Hofer and Taubes’s theorem, and the conjecture in the volume preserving case.The construction of Birkhoff sections, the concept of left handed vector field, and conjectures concerning geodesic flows in negative curvature.