Viscosity of milk has been one of the key issues faced by dairy industries today, especially during evaporation and atomisation processes. Up to date, most of the literatures on milk viscosity measurements were conducted based on reconstitution of milk powders. Such viscosity measurements do not necessarily reflect on the true nature of fresh milk. The aim of this study is to provide a comparison of milk viscosities between reconstituted milk and fresh milk, and milks with various heat-treatments. Here, for fresh milk, the medium-heat treated skim milk at 30% w/w is further concentrated under vacuum at 65°C. The study provides a range of viscosities values against solids concentration, which are useful in fine-tuning multi-stage falling-film evaporators for achieving smooth operations. One example of the model based scheduling of evaporation process is also given using a computer simulation program developed at Monash University.