The dissertation is based on two empirical studies that have the common aim of expanding our knowledge of the possibilities available to social workers to develop and carry out structurally oriented community work within the municipal social services. The first study, conducted in 1982-1984, was part of a larger study of the implementation of the Social Services Act. It was designed as a case study of four municipalities in Sweden, each of which had different structural characteristics (Suburbia, Bigtown, Middletown and Countryside). In the beginning of the 1990s (1991-1993) a follow-up study was made of these four municipalities. The study as a whole can be characterised as an example of the qualitative case study research approach. Three central problems are treated in the dissertation: a) What were the extent and direction of the structurally oriented interventions carried out in the four municipalities during the 1980s? b) What effect did the actors themselves and the municipal organisation have on the possibility of the social services to develop and carry out such interventions? c) What effect did the purchaser-provider model have on this endeavour? The concepts of power, welfare state and profession are discussed as being of central importance to the conclusions reached in the study. The development that took place in the municipalities can, in summary, be described as a professionalisation of the strategies for participatory community planning and a de-professionalisation of community and neighbourhood work. The dissertation shows that the social services were both successful and unsuccessful in the 1980s in their attempts to develop methods to effect changes on the structural level of the municipality. The analysis shows that both the successes and the failures depend on the complex interplay of various sources of power: the power of specific individuals and interest groups, the power of ideology, the power of the profession, and the power of the organisation.