Recent years have witnessed the rapid diffusion of electoral gender quotas. Today, about fourty countries around the world have introduced gender quotas for parliamentary elections, either by constitutional amendment or electoral law. Also, quotas for public election have been laid down in major political parties' statutes in more than fifty countries. This article, which is based on the first worldwide overview of the use of quotas, presents general trends in quota adoption. It identifies two discourses: the incremental track versus the fast track to women's parliamentary representation, and argues that the Scandinavian countries – which represent the incremental track – may no longer be a valid model for ways to improve women's representation. The article also analyses the implementation process, and concludes that, without specifications of quota provisions that match the electoral system in question, and rules about the rank order of candidates as well as sanctions for non-compliance, quota provisions may be merely symbolic.