Method, system, and computer program product for faceted search with relationships between categories are provided. The method includes: having a document set of multiple documents, each document having associated categories to which it belongs; grouping multiple categories associated with a document into a category set based on a relationship between the multiple categories; associating the category set with the document; and indexing the category set for retrieval of documents from categories sharing a category set. Wherein indexing the category set includes: having an index entry of a textual representations of a category, wherein the index entry includes a single occurrence for each document to which the category is attached; adding a payload to a document occurrence of a serialization of an identifier of the category sets to which the category belongs associated with the document. Indexing the category set further includes: adding an index entry for category set data, wherein the index entry includes a single occurrence for each document, wherein a document occurrence includes a payload of a serialization of an identifier of category sets associated with the document, and an identifier of the categories belonging to the category sets.