Social and professional connections developed at work help individuals in their career and provide benefits for firms too. Extensive work in labor economics has therefore investigated the formation of social ties at workplaces and their impact on job moves. More recently, methodological developments in economic geography have enabled us to look at the role of co-worker ties in more aggregate outcomes such as productivity growth of regions and of firms. This chapter provides an overview of the conceptual and methodological framework of co-worker network analysis in economic geography. The toolset includes survey data collection, network generation from administrative data sets on the individual-, firm-, and network levels, as well as econometric analysis, in which inter-firm co-worker network effects are disentangled from labor flows. By summarizing these methodological tools, the major results and future research directions, the chapter highlights the importance of network research in economic geography.