The New Towns Act 1946, initiated an era of town construction according to a national policy. In Scotland five New Towns are being built. Of these, East Kilbride is reaching the final stages, while Irvine's first immigrants settled in August 1969. The Towns, under the control of Development Corporations, have been planned so that the limitations of inter -war housing estates are avoided. In particular, emphasis has been laid on transport networks that facilitate communications, and on the establishment of self-contained communities. In the first New Towns construction of neighbourhood units was considered an appropriate method of overcoming anonymity in a town, and an aid to promoting the welfare of immigrants. Other kinds of residential units have been planned in the more recent towns. Problems of creating a self-contained, balanced neighbourhood are aggravated by an immature age structure and socio- economic imbalance. The study takes into account the physical and social structure of the residential units in East Kilbride, Glenrothes and Livingston; and reveals that in none of them have neighbourhoods come into existence through the continued interaction of residents throughout the area planned as a unit. The provision of facilities such as shops, schools, and clinics aids the self- containment of a unit, but not necessarily its cohesiveness which is related to the extent and frequency of the use, rather than the existence of facilities. Investigation of the patterns relatin;- to shopping, employment, churches and schools attended, recreation, and visiting habits, has shown that the effectiveness of neighbourhood boundaries is only partly a result of their physical character. Movement across a boundary is influenced primarily by the attraction of features on the other side. Furthermore, if facilities within the residential unit are not sufficiently attractive, the high level of mobility in the New Towns permitt residents to pursue activities beyond their own units. Cohesive qualities of residential units are related partly to the size of the unit, and to the proximity of the population's earlier homes which provide a strong attraction away from the unit. A sense of cohesion could be inculcated through participation in organisations whose membership is drawn from the residential unit, or whose activities are related directly to the unit, but these have proved of little consequence as few organisations cater specifically for people within one unit, and society membership within a unit is characteristic of only a small proportion of the New Town populations. Instead of residential units becoming cohesive entities most of them are comprised of a number of sub -regions related to the socio- economic structure, to the demographic characteristics, to the stage at which the area was built in the development of the unit, and to the influence exerted on a small area by a focal point either within or outwith the unit. Lack of a major focal point in a unit, a heterogeneous population and a good communications network for public and private transport permitting easy access to nearby centres, are not conducive to the establishment of a cohesive neighbourhood.