A system and method are provided for automatically invalidating cached data. A cache system caches data from a data server (e.g., web server, application server, database). When a request is received at the cache system from a client, particularly a request to alter or replace a set of data, the request is examined and may be compared to a set of rules or data relationships that invoke automatic invalidation. Based on a pattern or content of the request (e.g., an identifier of data to be changed), the cache system identifies and invalidates a cached data item without waiting for the data server to receive the request, process it and instruct the cache system to invalidate the data item. In a cache system comprising multiple caches, one cache may notify another when automatic invalidation is necessary.