Paramyxoviruses constitute a large family, including human animal pathogens with high prevalence and also major economic impact. During last fifteen years, development of reverse genetic systems, which allow generating viruses from cloned cDNA, revolutionized research on Paramyxoviruses. From the elaboration of minireplicons to the constitution of performing reverse genetic systems, this new strategy contributed to our understanding of viral cycle, pathogenicity or viral assembly, for example. This approach opened the way to the development of viral vectors and live-attenuated vaccines that could be useful tools in therapeutics and prophylaxis.