Aspects of a method and system for hash table based routing via table and prefix aggregation are provided. Aspects of the invention may enable aggregating prefixes of varying lengths into a single hash table, wherein each entry in the hash table comprises one or more encoded bits to uniquely identify said prefixes. Additionally, an entry in a hash table may be formatted based on a length of one or more representations of said prefixes in the entry. Aggregating prefixes into a hash table may comprise truncating the prefixes to a common length. In this regard, the encoded bits may indicate the length of the prefixes prior to and/or subsequent to truncation. Additionally, the encoded bits may represent bits removed from the prefix during truncation. In this regard, an encoded bit may represent a possible combination of removed bits and may be asserted when the removed bits are equal to that combination.