Here, we present a protocol for the isolation of endothelial cells (ECs) from tissues. ECs make up a minor population of cells in a tissue, but play a major role in tissue homeostasis, as well as in diverse pathologies. To understand the biology of ECs, characterization of this cell population is highly desirable, but requires the availability of purified cells. For this purpose, tissues are mechanically minced and subsequently digested enzymatically with collagenase and dispase. ECs in the resulting single-cell suspension are labeled with Abs against EC surface antigens and separated from the remainder of the cells and debris by capture with magnetic beads or by high-speed cell sorting. Purified ECs are viable and suitable for characterization of diverse cellular properties. This protocol is optimized for human tissues but can also be adapted for use with other species. Depending on the tissue, the procedure can be completed in ∼6 h.