A layer of cream (or fat) that forms on ultra-high-temperature processed milk during storage can make it unacceptable to the consumer. Milk homogenized after ultra-high-temperature treatment is apparently more susceptible to forming a cream layer than milk homogenized before the heat treatment. However, this study shows that milk homogenized after indirect ultra-high-temperature treatment has both a microstructure, as determined by transmission electron microscopy and immunogold labelling, and a cream layer thickness similar to that of milk homogenized before indirect ultra-high-temperature treatment, suggesting that it is feasible to homogenize milk before ultra-high-temperature treatment. Also, directly heated milk had a microstructure similar to that of indirectly heated milk. The locations of the caseins (κ-casein, αS1-casein and β-casein) and whey proteins (β-lactoglobulin and α-lactalbumin) were localized with the immunolabelling procedure. β-Lactoglobulin and κ-casein were found to be important proteins in forming the fat globule membrane of homogenized ultra-high-temperature processed milk and were localized on the fat globule membrane. The micrographs confirm that κ-casein dissociates from casein micelles on heating.