This article introduces an approach to tailoring behavior-change campaigns to target populations using the example of solid waste reduction in Santiago de Cuba. Tailoring is performed in the following steps: (1) Psychological constructs are selected to detect problems in performing the target behavior, and data are gathered on these constructs. (2) Cluster analyses are performed on these data to identify different psychological types and their distribution in the population. (3) Intervention techniques are assigned according to the spatial and quantitative distribution and the characteristics of these types. Results of the cluster analyses are presented for three different behaviors that can reduce the amount of deposited solid waste (recycling, composting, reuse) on the basis of the four psychological constructs of instrumental and affective attitude, difficulty, and social pressure. The tailoring of interventions could be used to design environmental campaigns more efficiently. (Contains 3 tables and 7 figures.)