At the end of the 20th century, nine new towns were developed in France: five on the outskirts of Paris (Évry, Melun-Sénart, Marne-la-Vallée, Saint-Quentin-en-Yvelines, Cergy-Pontoise) and four located near other major metropolitan areas (Le Vaudreuil/Rouen, Villeneuve d’Ascq/Lille, L’Isle d’Abeau/Lyon, Rives de l’Etang de Berre/Marseille). These new towns, which were intended to accommodate 100,000 to 500,000 inhabitants, were planned between 1965 and 1969 by France’s Welfare State in order to cope with metropolitan growth. However, projects likely to meet this objective had yet to be defined. While the State provided new planning tools (Land Orientation Act, 1967), the issue was handed over to multi-disciplinary design offices created on each construction site. How was their ambitious mission brought to life, and what did it achieve? These questions have remained largely unanswered due to a lack of expert knowledge and inquiry into this matter. Literature on the history of urban planning in France has already dismissed these new towns as failed experiments, considering them to be the last “avatar” of modernism (Roncayolo, 2001) — in line with mass housing projects, seen as symbols of the Government’s failure to provide adequate living environments. Nonetheless, research is underway to gain better insight into the recent past. In furtherance of this research, the aim of this paper is to reassess the place of French New Towns in urban history and urban planning. My hypothesis is that these projects were the result of a productive marriage between 20th-century urban planning expertise and the post-war CIAM debate on “Habitat,” which led to the birth of new avant-garde proposals. To develop this idea, I will draw on my ongoing analyses (based on a review of current literature, archival research and field surveys), comparing the first urban and architectural experiments carried out in three new towns: Le Vaudreuil, Évry and Villeneuve d’Ascq.