Industrial marketers can hardly be blamed for feeling that segmentation is very difficult for them. Not only has little been written on the subject as it affects industrial markets, but such analysis is also more complex than for consumer markets. The problem is to identify the best variables for segmenting industrial markets. The authors present here a “nested” approach to industrial market segmentation. Separated according to the amount of investigation required to identify and evaluate different criteria, the layers are arranged to begin with demographics as the area easiest to assess. Then come increasingly complex criteria, including company variables, situational factors, and personal characteristics. The authors warn, however, that a nested approach cannot be applied in cookbook fashion but rather must be adapted to individual situations and circumstances.