To explore communication patterns within organizations, a network analysis was conducted of a large New York financial institution with 98 departments and 66 branches. Functional analysis revealed that departments had more and stronger communication linkages than did branches. Departments were also closer in communication distances than branches. Branches, however, showed higher levels of integration than departments. These results suggest that, in investigations of highly differentiated, complex organizations, focusing on the communication patterns of functional units, rather than of individuals, eases problems in data collection and avoids unreliable self-reports. (MM)