The use of flow cytometry in heat-shock protein (HSP) research is increasing rapidly due to the high sensitivity and versatility of the technique. The method allows the simultaneous analysis of multiple proteins within numerous cell types in a heterogeneous sample, providing advantages over alternative techniques, such as ELISA and Western blotting. As a result, flow cytometry is becoming the leading technique used in this area of research. The current chapter describes the methodology for preparing samples for this technique and outlines two protocols for the analysis of surface- and intracellular-localised HSPs.