Interactions between tumor cells and their microenvironment have been long established as a cardinal hallmark of tumorigenesis and metastasis. To that end, tumor-associated macrophages (TAMs) have been studied extensively and were found to be typically correlated with poor prognosis in various cancers. TAMs are key elements of cancer-associated inflammation promoting cancer progression by increasing angiogenesis, inducing immunosuppression of the tumor tissue, and remodeling the extracellular matrix favoring invasion and metastasis. Since resident macrophages are characterized by substantial diversity and plasticity, understanding their polarization patterns in response to microenvironmental cues is a prime focus in the field. This chapter demonstrates an efficient manner to characterize polarization patterns of macrophages inside tumor tissues.