In the publish/subscribe paradigm, information providers disseminate publications to all consumers who expressed interest by registering subscriptions with the publish/subscribe system. This paradigm has found widespread applications, ranging from selective information dissemination to network management. In all existing publish/subscribe systems, neither subscriptions nor publications can capture uncertainty inherent to the information underlying the application domain. However, in many situations, knowledge of either specific subscriptions or publications is not available. To address this problem, this chapter proposes a new object-oriented publish/subscribe model based on possibility theory and fuzzy set theory to process imperfect information for expressing subscriptions, publications, or both combined. Furthermore, the approximate publish/subscribe matching problem based on fuzzy measures is defined, and the real-world A-ToPSS™ system is described.