One of the most general and relevant dynamical phenomena observed in the mammalian brain are the rhythmic coherent behaviors involving different neuronal populations. Collective oscillations are commonly associated with the inhibitory role of interneurons. However, coherent activity patterns have been observed also in ``in vivo'' measurements of the developing rodent neocortex and hyppocampus for a short period after birth, despite the fact that at this early stage the nature of the involved synapses is essentially excitatory. Independently, theoretical studies of fully coupled excitatory networks of leaky integrate and-fire (LIF) neurons have revealed the onset of macroscopic collective periodic oscillations (CPOs). We investigate the onset of CPOs in a diluted excitatory pulse-coupled network of leaky-integrate-and-fire neurons in the presence of quenched and annealed topological disorder. We find that the disorder induces a weak form of chaos, which vanishes in the thermodynamic limit. In the limit of large N the collective dynamics converge to that of the fully coupled network with a properly rescaled synaptic strength. Therefore CPOs are robust to the presence of annealed and quenched disorder in the network.