This paper aims to provide an overview of the legal regulation of same sex couples in Spain and Catalonia. It will present how regulations have evolved, from legal disregard of same sex couples to the admission of same sex marriages by the Spanish Law in 2005, upheld by the Spanish Constitutional Court. Reference will be made to Catalan law, as it provided the first comprehensive regulation on same-sex cohabitation. And finally, it will highlight some challenges still faced by same sex couples, as regards assisted reproduction.