This work investigates the performance of laser induced breakdown spectroscopy (LIBS) for the detection and characterization of nanoparticles generated by spark discharge generators (SDG) and arc discharge generators (ADG). LIBS nanoaerosol analysis was carried out according to both on-line (in a gas stream) and off-line (after collection on a filter) methodologies for monometallic (Cu and Au) and bimetallic (AgCo, SnCu, AgAu) nanoparticles generated by ADG and SDG. It was shown that LIBS is not only capable of detecting the presence of nanoparticles in real time, but LIBS spectra can also be used to provide qualitative and quantitative compositional information, as well as estimates for the particle number concentration. This analytical capability, combined with the compact and robust character of LIBS instrumentation, can be put to use for the real-time monitoring of industrial gas-phase nanoparticle synthesis or environmental or workplace exposure to nanoparticles.