We examine how the structure and content of individuals' networks in the workplace affect intraorganizational mobility. Consistent with prior research, we find that an individual's mobility is enhanced by having a large, sparse network of informal ties for acquiring information and resources. However, in contrast to previous work, we emphasize the importance of consistent role expectations for performance and mobility. We find evidence that well-defined performance expectations are more likely to arise from a small, dense network of individuals. We develop a typology of network contents and document the interaction between network structure and content in analyses of mobility among employees of a high-technology firm. We also examine how the effects of tie duration on mobility vary by tie content. We discuss the implications of our results for theory and research on networks and organizational mobility.