I present empirical findings from an observational study of female municipal middlemanagers who are home help assistants in elder care. The observations showed that the home helpassistants’ sphere of activity was influenced by two distinct patterns: the official line organizationand the invisible horizontal social network. I first give a brief description to the immediate backgroundof the present study. Then I describe the line organization and give two empirical examplesof information exchange where the practical implication of the line organization at different levelsis visible. However, the study also revealed another pattern opposed to the line organization, calledthe horizontal network. I will give an empirical example of an incident that illustrates how the homehelp assistants use a social network to solve problems and to make judgments. The study showed thatthese networks are not persistent – they are rebuilt depending upon context. Members of the networkcan be people both within and outside the municipal organization. Decisions and problem solving arethus conducted in a process of interaction and negotiations with other people. The social networks arenot visible in the official organizational description. Still they form the foundation for the home helpassistants’ work and influence their ideas of how the work should be conducted. Finally I discusssome implications of the line organization and the social network and the possible consequenceswhen introducing new technology, i.e., computers in work. In this case the computers were plannedto support the line organization but not the work practice of social networks.