The production of pions in nuclear collisions is analyzed in terms of a microscopic reaction model, where the free energy of the entrance channel is transferred to the final channel through the coupling of the relative motion to the internal excitation of N*-resonances. Such a model allows quite naturally for a consistent analysis of the exclusive and the inclusive production of pions. It turns out that the pionic fusion cross section is determined predominantly by the spectroscopic parentage between the initial target projectile combination and the final nucleus, whereas the inclusive part is dominated by the energy dependence of the phase space factor, i.e. by the number of the degrees of freedom which are relevant in a given kinematical situation. This model is applied to the analysis of available experimental data from threshold to the A(1232)-region. A consistent analysis of both the inclusive and the exclusive part of the pion spectrum is presented. 24.90.+d; 25.10.+s; where A 1 and A 2 denote the target and the projectile and A the (bound) united nucleus, the total free energy of the system available in the entrance channel is converted into the creation of the outgoing pion. Thus the transition operator for this process necessarily has to be a genuine many body operator. In such a coherent reaction there are no spectator nucleons. In the exclusive two body reaction -in the following referred to as pionic fusion -it is evident that the microscopic properties of nuclei, i.e. the nuclear structure, both in the entrance channel (e.g. the target projectile combinations) and in the final channel determine the probability for this cold fusion process. Furthermore, the internal structure of the nuclear constituents plays an important r61e since in the relevant energy range the internal quark excitations of the nucleons, i.e. the baryon resonances, couple strongly to mesonic decay channels. These aspects will be discussed in Sect. 3.