In general, embodiments of the present invention provide an approach for caching potentially repetitive data in a publication-subscription (pub/sub) environment. Specifically, in a typical embodiment, when a message is received on a broker system from a publisher system, the broker system analyzes the message for potentially repetitive data. Such data can be determined from historical messages (e.g., determining that a certain set of data appeared in multiple messages and is thus flagged in a database or the like), a set of rules (e.g., if data set “Y” appears, flag it as potentially repetitive), etc. Regardless, once such a set of data has been identified, the set of data will be cached, and a unique identifier/tag corresponding thereto will be sent to the publisher system and to applicable subscribers. Thereafter, any subsequent message including the same data will contain the unique identifier in place of the cached data (i.e., an abbreviated message). The abbreviated message can be sent from the publisher system to the broker system, and then onto the subscriber system, which will retrieve the data from the shared cache and replace the unique identifier in the abbreviated message with the cached data to yield a complete message. Thus, once data has been cached, there is only a need to send an abbreviated message, which will save network bandwidth.