Ab inito molecular dynamics, although still challenge, is becoming an available tool for the investigation of the photodynamics of aromatic heterocyclic systems. Potential energy surfaces and dynamics simulations for three particular examples and different aspects of the excited and ground state dynamics are presented and discussed. Aminopyrimidine is investigated as a model for adenine. It shows ultrafast S1-S0 decay in about 400 fs. The inclusion of mass-restrictions to emulate the imidizole group increases the lifetime to about 950 fs, a value similar to the lifetime of adenine. The S2-S1 deactivation, typical in the fast component of the decay of nucleobases, is investigated in pyridone. In this case, the S2-state lifetime is 52 fs. The hot ground-state dynamics of pyrrole starting at the puckered conical intersection is shown to produce ring-opened structures consistent with the experimental results.