Regionality, frequently called terroir, is often used as a way to market wines from different locations. In this chapter we will discuss the chemical and sensory effects of regionality using thirty commercially made Australian Cabernet Sauvignon wines as well as forty one research lots of Californian and Argentinean Malbec wines. In both studies the volatile profiles of the wines separated the regions from one another. The separations based solely on sensory descriptive analysis data was less clear cut for the Cabernet wines and more so for the Malbec wines. When the volatile chemical and sensory data were combined separating regions was possible for both sets of wines. These studies showed that for both very well controlled research fermentations and for less controlled commercial fermentations it is possible to determine sensory and chemical regional differences for wines. The effect of region on the quality of wine is a very old concept as seen by the writings of Pliny and Columella (1). Around 1825 James Busby stated ". we sometimes see, under the same climate, very different qualities of wine, because the differences of soil, exposure, or culture, modify the immediate influence of this grand agent" (2). In the more modern era the concept of terroir has received a great deal of popular press and there are numerous scientific publications on terroir. The listed references are a selection of recent publications (3-6). We prefer the word 'regionality' to the more emotionally charged 'terroir' and will use that in this manuscript. We include growing conditions, microbial differences in vineyrads and wineries as well as common regional winemaking practices in our concept of regionality. We also believe that distinguishing regions by sensory and/or chemical means are useful in the elucidation of regionailty. We will describe the sensory descriptive analysis and volatile profile analyses used to describe the differences among Cabernet Sauvignon wines from different regions in Australia and among Malbec wines from different regions in Argentina and California.