This article seeks to analyse the reciprocal influence between the post-war urban planning policies and the development of residential neighbourhoods in Lelystad between 1965 and 1990. This city has been designed ‘from scratch’ as the urban centre of the IJsselmeer Polders, the largest land reclamation project of the Netherlands. Lelystad’s neighbourhood development will be described and contextualised in the Dutch New Towns planning policy (1960–1985), which intended to avoid increasing congestion in the most densely populated area in the Netherlands: the Randstad. Lelystad is seen as a significant case. This New Town exemplifies the evolution in urban planning in The Netherlands in the second half of the twentieth century. Cornelis van Eesteren, who had presided over the CIAM (Congrès Internationaux d’Architecture Moderne) from 1930 to 1947, was responsible for the urban design in 1964, based on the principles of the Modern city and the functionalist design of residential neighbourhoods. However, Van Eesteren was dismissed, and his plan was modified. The successive urban plans, elaborated by the IJsselmeer Polders Development Authority (a public body for the development of the polders), adopted a technical and practical approach, and later moved to functionally integrated neighbourhoods, based on more organic ‘Woonerf’ theories. The research investigates the relationship between the general and the particular by studying the socioeconomic and political context that conditioned the Dutch New Towns and the specific urban and architectural characteristics of a selection of residential ensembles in Lelystad’s neighbourhoods. Furthermore, the research seeks to illustrate the relevance and the influence of both urban planning policies and the effective design of residential configurations.