Adipose tissue contains cell types other than adipocytes that may contribute to complications linked to obesity. For example, macrophages have been shown to infiltrate adipose tissue in response to a high-fat diet. Isolation of the stromal-vascular fraction of adipose tissue allows one to use flow cytometry to analyze cell surface markers on leukocytes. Here, we present a technical approach to identify subsets of leukocytes that differentially express cell surface markers.